Before the
Federal Communications Commission 
Washington, D.C 20554
FCC 96 -285 
In the Matter of )
Access to Telecommunications ) CC Docket No. 87-124
Equipment and Services by Persons )
With Disabilities )
REPORT AND ORDER
Adopted: June 27, 1996 Released: July 3,1996 
By the Commission:
TABLE OF CONTENTS
Paragraph No. I. Introduction 
1
n. Background 2 
ffl. Discussion 7
A. Statutory Issues 7
1. Commission Authority Under the HAC Act 7
2. Other Statutes 14
a Americans With Disabilities Act 14
b. The Telecommunications Act of 1996 21
B. Telephones in Specific Settings 23
1. Workplace Telephones 23 
a General Requirements and
Implementation Schedules 23 i b. 
No Retrofitting Requirements 28 
c. Workstation Requirements and
Headset Exemption 31 
d. Rebuttable Presumption 35 
e. Replacement and Newly Acquired
Telephones 40 
f. Safe Harbor 42
2. Confined Settings 47
3. Hotels and Motels 53
8249
4. Cost of Compliance 60
C. Volume Control
1. Background 60
2. Requiring Volume Control 63
a. Statutory Authority 64
b. Need for Volume Control Requirement 66
c. Costs and Availability 70
3. Inclusion in Definition of
Hearing Aid Compatibility 76
4. Transition Period 81
5. Technical Standard 83
a. Background 83
b. Feasibility 84
c. Modifications to Technical Standard 88
d Miscellaneous Issues 92
D. Equipment Labeling 98 
E. Consumer Education 103
IV. Conclusion 106
V. Regulatory Flexibility Act Analysis 107
VI. Ordering Clauses 108 
Appendices:
A List of Parties
B. Final Regulatory Flexibility Analysis
C. Final Rules
D. Standards Incorporated by Reference: Paragraph 4.3.2 of ANSI/ELVTIA-579- 
1991; TFEF, Standard TFFF. 661-1979; and Section 7.4 of IEEE Standard IEEE 
269-1991
8250
L INTRODUCTION
1. In this Report and Order, we amend our rules to ensure access by persons who 
use hearing aids to the nation's telephone network. Specifically, we amend our rules to 
provide that, eventually, virtually all wireline telephones in workplaces, confined settings, and 
hotels and motels must be hearing aid compatible.1 We also require that, eventually, to be 
considered hearing aid compatible, telephones must offer both electro-magnetic coil 
compatibility2 and volume control. Finally, we require that new telephones be labeled hearing 
aid compatible. These actions are taken pursuant to the Hearing Aid Compatibility Act of 
1988 (HAC Act).3
tt BACKGROUND
2. The HAC Act required the Commission to establish regulations that would 
ensure reasonable access to telephone service by persons with hearing disabilities.4 As part of 
its implementation of the HAC Act, in 1992 the Commission adopted rules that expanded the 
requirements to provide hearing aid compatible telephones to particular establishments.5 The 
rules required that, with minor exceptions, all telephones in hospitals and other health care 
facilities, in hotels and motels, in prisons, and in all workplaces be made electro-magnetic 
coil hearing aid compatible by May 1, 1993, for establishments with twenty or more
1 As currently defined, "hearing aid compatibility" describes a feature internal to a telephone 
(distinct from external portable devices that plug into a telephone) that enables a person with a 
hearing aid designed to be used with a telephone to use that telephone. See 47 U.S.C. § 
610(bXlXB).
2 "Electro-magnetic coil hearing aid compatibility" exists when a hearing aid contains a 
telecoil that detects, or is compatible with, a similar coil in a hearing aid compatible telephone. 
The coil in the telephone converts electrical energy into magnetic energy, which is then detected 
by the telecoil in the hearing aid. See NPRM at para. 10.
3 47 U.S.C. § 610(a).
4 47 U.S.C. § 610(a).
5 Access to Telecommunications Equipment and Services by the Hearing Impaired and Other 
Persons with Disabilities, CC Docket No. 87-124, Report and Order. 7 FCC Red 3472 (1992) 
(1992 Order) at Paragraph 1. See also First Report and Order. 4 FCC Red 4596 (1989) (First 
R&Q): Memorandum Opinion and Order and Further Notice of Proposed Rule Making. 5 FCC 
Red 3434 (1990) (MO&OX recon. denied 6 FCC Red 4799 (1991); Order. 8 FCC Red 4958 
(1993) (Order;): Notice of Proposed Rulemaking. 11 FCC Red 4338 (1995) (NPRM): Order 
Granting Motion for Extension of Time to File Comments. 11 FCC Red 1814 (1996) (Time 
Extension Order).
8251
employees, and by May 1, 1994, for establishments with fewer than twenty employees.6
3. After the Commission's adoption of these rules, many establishments reported 
to the Commission that they were encountering serious difficulties in their attempts to 
comply. The difficulties generally related to the costs of retrofitting existing telephones, and 
to the establishments' ability to retrofit telephones by the prescribed deadline. On February 
22, 1993, the Commission placed on public notice a petition received from Goodwill 
Industries of Seattle for waiver of the new rules. Written comments on this Goodwill petition 
and additional petitions for waiver were filed by forty-nine individuals and organizations. 
On April 2, 1993, the Tele-Communications Association7 filed an Emergency Request for 
Stay of the HAC requirements. On April 13, 1993, the Commission suspended portions of 
the new rules affecting workplaces, confined settings and hotels and motels.8
4. An Emergency Request to Reinstate the suspended rules was then filed by the 
Alexander Graham Bell Association for the Deaf on May 12, 1993. In light of the ongoing 
controversy, the Commission asked for public comment on whether an advisory committee to 
develop new rules should be formed.9 Commenters overwhelmingly supported the formation 
of an advisory committee, and thirty-nine nominations were received by the Commission. In 
March 1995, the Commission announced the establishment of a nineteen-member Hearing Aid 
Compatibility Negotiated Rulemaking Committee (Committee) under the Negotiated 
Rulemaking Act of 1990.10 The Commission selected members of the Committee to ensure 
representation from all parties interested in the status of the suspended rules. Committee 
members represented large and small businesses and other employers, the telecommunications 
industry, consumers with hearing disabilities, the health care industry, and the hotel and motel 
industry.11 The Committee's task was to consider whether the suspended rules should be 
reinstated, or new rules proposed.
C.F.R. §§ 68.112 (bXl), (3), (5).
7 The Tele-Communications Association changed its name to The Information Technology 
and Telecommunications Association in September, 1995. The organization is referred to as 
"ITTA" herein.
8 See NPRM at paras. 5-6; see also Order at 4958-4959. For a description of which rules 
were suspended, and which were not, see NPRM at para 6.
9 FCC Asks for Comments and Nominations for Membership Regarding the Establishment 
of an Advisory Committee to Negotiate Regulations, Public Notice. CC Docket No. 87-124 
(November 1, 1994).
10 See Negotiated Rulemaking Act of 1990, 5 U.S.C. § 561. 
U N2EM at paras. 2,8.
8252
5. Committee members met face-to-face around a bargaining table over an eight- 
week period and reached full consensus on the entire work program. In August 1995, the 
Committee presented a Report to the Commission.12 The Committee recommended that, in 
place of the suspended rules, the Commission adopt new rules for workplaces, confined 
settings, and hotels and motels that would cover both telephone electro-magnetic coil 
compatibility and volume control. On November 28, 1995, the Commission adopted and 
released a NPRM that proposed the rules recommended by the Committee.
6. In response to the NPRM thirty-one comments and six reply comments were 
filed.13 The majority of commenters support the proposed rules. Numerous commenters 
representing individuals with hearing and speech disabilities, and industry, labor and 
government organizations filed comments expressing overall support, directing their 
comments to a narrow range of issues, including workplace and volume control rules.14 Six 
commenters expressed general opposition to the proposed rules, mainly on the grounds that 
the Commission exceeded its statutory and rulemaking authority.15
ffl. DISCUSSION 
A. STATUTORY ISSUES
1. Commission Authority Under the HAC Act 
a. Background
12 Report of the Federal Communications Commission Hearing Aid Compatibility Negotiated 
Rulemaking Committee, CC Docket No. 87-124, August 1995 (HACNRC Report).
13 See Appendix A for a listing of parties filing comments and reply comments.
14 See, e.g.. Comments of the Alexander Graham Bell Association for the Deaf (AGB), 
American Speech-Language-Hearing Association (ASHA), American Health Care Association 
(AHCA), Association of College and University Telecommunications Administrators (ACUTA), 
Chicago Hearing Society (CHS), Communications Workers of America (CWA), U.S. General 
Services Administration (GSA), HANDS, Inc., Hearing Industries Association (HLA), IMPACT, 
Inc., Information Technology and Telecommunications Administration (ITTA), League for the 
Hard of Hearing (LHH), National Association of the Deaf/National Center for Law and Deafness 
(NAD/NCLD) Newspaper Association of America (NAA), Pittsburgh Hearing and Speech 
Resources, Inc., Self Help for Hard of Hearing People, Inc. (SHHH), Telecommunications for 
the Deaf, Inc. (TDI) and Wisconsin Center for the Deaf and Hard of Hearing.
15 See Comments of American Bankers Association (ABA), Credit Union National 
Association (CUNA), Equal Employment Advisory Council (EEAC), Food Marketing Institute 
(FM), National Association of Manufacturers (NAM),.and National Federation of Independent 
Businesses (NFIB).
8253
7. The HAC Act requires the Commission to "establish such regulations as are 
necessary to ensure reasonable access to telephone service by persons with impaired 
hearing."16 The HAC Act also requires the Commission to ensure that all "essential" 
telephones are hearing aid compatible.17 The statute defines "essential telephones" as "coin- 
operated telephones, telephones provided for emergency use, and other telephones frequently 
needed by persons using such hearing aids."18 The Commission determined that the term 
"telephones provided for emergency use" includes workplace telephones, telephones in 
confined settings, and hotel and motel telephones, and accordingly required in a 1992 Report 
and Order, and proposed again in its November 1995 NPRM. that telephones in these settings 
must be hearing aid compatible.19
b. Comments
8. ABA, CUNA, EEAC, FM, NAM and NFffi assert that the Commission's 
proposed rules, in particular rules applicable to the workplace, exceed Congressional intent 
and Commission authority under the HAC Act. They argue, among other things, that 
Congress did not intend the term "essential telephones" to encompass all workplace 
telephones. In support of this argument, EEAC points1 to legislative history from the 
Telecommunications for the Disabled Act of 1982 (1982 Act),20 which was the predecessor to 
the 1988 HAC Act. Congress passed the 1988 HAC Act because it found, among other 
things, that the 1982 Act "did not guarantee the nation's hearing impaired complete access to 
the telephone network,"21 The 1982 Act legislative history states that "under no 
circumstances may the Commission designate as an essential telephone any residential 
telephone or any other telephone if all the persons who would normally use it do not have 
hearing impairments."22 In addition, EEAC and NAM23 assert that the HAC Act was only 
intended to impose the responsibility of providing hearing aid compatible telephones upon
16 47 U.S.C. § 610(a).
17 47 U.S.C. § 610(b)(lXA).
18 47 U.S.C. § 610(bX4XA).
19 See Report and Order. 7 FCC Red at 3472 (1992); NPRM at paras. 26, 46 and 53.
20 Pub. L. 97-410, 96 Stat. 2043 (Jan. 3, 1983).
21 KR. Rep. No. 674, 100th Cong, 2d Sess. 6 (1988).
22 H.R Rep. No. 888, 97th Cong., 2d. Sess. 9 (1982) (1982 Act House Report).
23 NAM Comments at 1-2; EEAC Comments at 6 - 8.
8254
manufacturers, and not upon employers.24
9. The National Association of the Deaf (NAD), four other national associations 
representing individuals with hearing and speech disabilities, and the Communications 
Workers of America (CWA) (collectively, "NAD Reply") filed joint reply comments 
addressing EEAC's arguments. NAD asserts that EEAC "misinterprets the purpose, effect and 
design of the proposed rules and ignores the intent of Congress to ensure full telephone 
access to individuals with hearing disabilities."25
c. Discussion
10. We find that the proposed rules are within the Commission's authority under 
the HAC Act. The HAC Act requires the Commission to "establish such regulations as are 
necessary to ensure reasonable access to telephone service by persons with impaired 
hearing."26 The Act also requires the Commission to ensure that all "essential" telephones are 
hearing aid compatible27 and defines "essential" telephones to include "telephones provided 
for emergency use, and other telephones frequently needed for use by persons using hearing aids."28
11. In adopting the HAC Act, Congress placed great weight on the "emergency 
use" provision of the "essential telephones" definition. The legislative history indicates that 
the term "telephones provided for emergency use" should be interpreted broadly and include 
workplace telephones. The Senate Report stated that "No matter how broadly the FCC 
defines 'essential,' it is impossible to specify in advance all the telephones that a hearing aid 
user might need. .. . jl]t is impossible to predict beforehand when an emergency situation 
may arise."29 The Senate Report also stated that "[emergencies may occur, for instance, at a 
friend's home or in another person's business or office. In short, the situations in which a
24 EEAC also argues that the proposed rules would require "wholesale retrofitting" and thus 
exceed the boundaries of the HAC Act. EEAC Comments at 5-8. We address this argument in 
paras. 28-30, infra.
25 NAD Reply Comments at 3.
26 47 U.S.C. § 610(a).
27 47 U.S.C. § 610(bXlXA).
28 47 U.S.C. § 610(bX4).
29 S. Rep. No. 391, 100th Cong, 2nd Sess. 3 (1988) (Senate Report).
8255
hearing aid user would need access to a telephone are innumerable."30 Similarly, in an 
introduction of the HAC Act on the House floor, Congressman Edward Markey stated: 
"[i]magine not being able to call home from a friend's house or use the phone in someone 
else's office or even to call 911 outside your own home in an emergency."31
12. We also find that the cited language from the 1982 Act legislative history does 
not support EEACs position. First, the purpose of the HAC Act was to "expand upon the 
1982 Act and provide a greater degree of assurance that hearing aid users can have access to 
a hearing aid compatible telephone."32 EEACs argument also ignores the emphasis which 
Congress placed on the emergency use provision when it revisited the "essential telephone" 
issue in 1988. Furthermore, even if the cited language were relevant, we do not see how this 
language in any way demonstrates Congressional intent to bar the Commission from declaring 
workplace telephones to be "emergency use" telephones.33 This language is primarily 
directed at telephones in private residences and other settings which are for the exclusive or 
private use of a few known persons.34 Places of employment and places of public 
accommodation, however, are frequented by many persons, including employees and visitors, 
and there is a greater likelihood that a person who is hearing impaired may need emergency 
access to a telephone in such settings. We believe, therefore, that EEAC overstates the scope 
of this Congressional language.
13. The argument that the HAC Act is limited only to manufacturing standards is 
erroneous. The HAC Act includes both a manufacturing requirement35 and a separate 
provision requiring the Commission to adopt rules ensuring that all "essential" telephones 
(including "emergency use" telephones) are hearing aid compatible.36 We believe it is 
consistent with the "essential" telephone requirement to require that the owner or lessee of 
essential telephones be responsible for ensuring that they are hearing aid compatible. This is 
inherent in the statutory concept of the Commission's rules requiring telephones to be
30 Id
31 134 Cong. Rec. H3985 (Daily Ed June 7, 1988)(statement of Rep. Markey).
32 Senate Report at 1.
33 See para, 11, supra.
34 We note that the House committee report on the 1982 Act used the terms "any residential 
telephone or any other telephone," whereas the House committee report on the 1988 Act, in 
addressing this issue, used only the words "any residential telephone." 1982 Act House Report 
at 9; H.R Rep. No. 674, 100th Cong., 2nd Sess. 12 (1988).
35 47 U.S.C. § 610(b)(l)(B).
36 47 U.S.C. § 610(bXl)(A).
8256
replaced.
2. Other Statutes
a. Americans with Disabilities Act 
(1) Background
014. The Americans with Disabilities Act of 1990 (ADA) is a comprehensive 
national mandate for the elimination of discrimination against individuals with disabilities.37 
Title I of the ADA prohibits discrimination against qualified individuals with disabilities in 
their place of employment, and requires covered employers to provide reasonable 
accommodations for employees with disabilities, if the provision of such accommodations 
would not pose an undue hardship.38 Title I of the ADA only applies to employers with 15 or 
more employees.39 Title I of the ADA does not apply to employees of Executive branch 
agencies of the U.S. Government.40
15. Titles n and HI of the ADA require all public entities (state and local 
government instrumentalities) and places of public accommodation (e.g.. places of lodging 
and health care facilities) to furnish auxiliary aids and services to individuals with disabilities 
when necessary for effective communication.41 "Auxiliary aids and services" under Title IE 
includes "telephones compatible with hearing aids."42 Finally, pursuant to Title IV of the 
ADA, the Commission is required to ensure that all states provide "functionally equivalent" 
telecommunications relay services (TRS) for individuals with hearing and speech disabilities 
who use text telephones (TTYs).43 Title IV, however, does not address the needs of persons
37 Pub. L. 101-336, 104 Stat. 328 (July 26, 1990), codified at 42 U.S.C. § 12101 - 12213; 
See 42 U.S.C. § 12101(b)(l).
38 See generally 42 U.S.C. 12111 - 12117.
39 42 U.S.C. §12111(5XA).
40 42 U.S.C. § 12111(5XBXi). But see 42 U.S.C. § 12209 (ADA generally applicable to 
Congress and the Legislative Branch of the U.S. Government).
41 See generally 42 U.S.C. §§ 12131 - 12189. Department of Justice regulations 
implementing Titles H and JJI of the ADA are codified at 28 C.F.R. Parts 35 and 36.
42 28 C.F.R. § 35.104.
43 Pub. L. 101-336, 104 Stat. 366 - 69, § 401, codified at 47 U.S.C. § 225. TRS is a 
telephone transmission service which uses specialized staff and equipment to "relay" telephone 
calls between voice telephone and text telephone (TTY) users. The Commission's regulations
8257
with hearing disabilities who have the ability to use voice telephones, with or without hearing 
aids.
(2) Comments
16. EEAC, CUNA, FMI, NAM, NFIB and ABA argue that the Commission's 
proposed workplace rules are unnecessary because they duplicate the provisions of the 
Americans with Disabilities Act. The ABA, for example, states that "[i]f the goal is to 
further reasonable access to telephone service by persons with hearing disabilities, the ABA 
feels that employers will have already met that goal by fulfilling their requirements under the 
Americans with Disabilities Act."44 The Commission also received informal comments 
regarding the NPRM from parties representing individual hotels and motels, arguing that the 
Commission's proposed rules for hotels and motels are unnecessary because the ADA already 
requires them to provide hearing aid compatible phones upon request to guests with hearing 
disabilities.
17. NAD points out in reply comments that the plain language of the ADA states 
that "nothing in this Act [ADA] shall be construed to invalidate or limit the remedies, rights, 
and procedures of any Federal law .. . that provides greater or equal protection for the rights 
of individuals with disabilities."45 NAD also argues that "the contention that the ADA 
adequately addresses the needs of individuals with hearing disabilities fails to consider the 
practical reality of most employment situations."46 NAD notes that "in the course of 
conducting daily business, emergency situations may arise that can require an individual to 
use a phone other than his or her own."47
(3) Discussion
18. The plain language of Title V of the ADA clearly states that it is not intended 
to invalidate any other Federal law which provides equal or greater protection for individuals 
with disabilities.48 The HAC Act provides a much greater degree of protection to individuals
implementing TRS are codified at 47 C.F.R.§§ 64.601 - .608.
44 ABA Comments at 2-3.
45 NAD Reply Comments at 8, citing 42 U.S.C. § 12201(b).
46 NAD Reply Comments at 7.
47 14 at 7-8.
48 42 U.S.C. § 12201(b).
8258
with disabilities than the ADA, in terms of access to hearing aid compatible telephones.49 We 
conclude, therefore, that the presence of the ADA does not obviate the need to implement the 
HAC Act, and we find any arguments to the contrary to be without merit.
19. We also conclude that the ADA, in and of itself, does not fulfill the 
Congressional mandate of the HAC Act to "eliminate the disparity between hearing aid-users 
and non-users in obtaining access to the telephone network."50 Merely providing hearing aid 
compatible telephones to individuals on an as-needed basis, as a "reasonable accommodation" 
under the ADA, does not provide the same degree of protection and access as required by the 
HAC Act, which provides, among other things, that all "essential" telephones must be hearing 
aid compatible.
20. Titles I through HI of the ADA do not completely address the many venues 
and locations where employees and patrons with hearing disabilities may need access to a 
telephone in the event of an emergency, including places of employment with fewer than 15 
employees and U.S. Government agencies. The HAC Act, on the other hand, places 
responsibility on these employers to offer such access, and ensures that nearly all public and 
private employees can have access to hearing aid compatible telephones in the workplace. 
Finally, while Title IV of the ADA does provide access to the telephone network for persons 
who use TTY equipment, a significant majority of individuals with mild to severe hearing 
disabilities does not use TTYs, but rather relies on residual hearing and/or hearing aids to use 
voice telephones directly. The Commission's rules under Title IV of the ADA, taken together 
with HAC Act rules which we adopt herein, form a seamless web of access to the telephone 
network by all individuals with hearing and speech disabilities.
b. The Telecommunications Act of 1996
21. Subsequent to the release of the Commission's NPRM in this proceeding, 
Congress enacted the Telecommunications Act of 1996 (1996 Act).51 Of particular relevance 
are Sections 255(b) and (d) of the 1996 Act, which require manufacturers of telecommuni 
cations equipment to ensure that equipment and customer premises equipment (CPE) is 
accessible to individuals with disabilities, or compatible with existing peripheral devices 
commonly used by individuals with disabilities, if readily achievable.52 The HAC Act, 
however, does not contain a "readily achievable" standard, but requires all telephones
49 ILg, see para. 20 infra.
50 Senate Report at 7.
51 Pub. L. 104-104, 110 Stat. 56 (1996).
52 14, § 255(b), (d). Section 255(a)(2) of the 1996 Act incorporates the ADA definition of 
"readily achievable" at 42 U.S.C. § 12181(9): "easily accomplishable and able to be carried out 
without much difficulty or expense."
8259
manufactured after August 16, 1989, and aJi essential telephones to be hearing aid compatible. 
Pursuant to Section 255(e) of the 1996 Act, guidelines for accessible telecommunications 
equipment and CPE are to be developed by the U.S. Architectural and Transportation Barriers 
Compliance Board, in conjunction with the Commission.53
22. We note that both the HAC Act and Section 255 of the 1996 Act share a 
similar goal, namely, access to the telecommunications network by individuals with 
disabilities.54 The 1996 Act, and its legislative history, do not discuss hearing aid 
compatibility or the HAC Act. Section 601(cXl) of the 1996 Act provides: "This Act and 
the amendments made by this Act shall not be construed to modify, impair, or supersede 
Federal, State or local law unless expressly so provided in such Act or amendments." As 
there is no language in the 1996 Act or legislative history to the contrary, we conclude that 
the HAC Act is unaltered by the 1996 Act, and that the Commission should continue to 
implement the more specific mandates of the HAC Act.
B. TELEPHONES IN SPECIFIC SETTINGS 
1. Workplace Telephones
a. General Requirements and Implementation Schedules 
(1) Background
23. The Commission's rules affecting workplace common areas were not suspended 
in our April 1993 Order. Common areas include libraries, reception areas and similar 
locations where employees are reasonably expected to congregate.55 Employers have had a 
continuing obligation since 1992 to ensure that all common area workplace telephones are 
hearing aid compatible, and these requirements were not modified by the HAC Negotiated 
Rulemaking Committee or our NPRM Much of the controversy surrounding our April 1993 
suspension was in regard to workplace non-common areas. In the NPRM, therefore, we 
proposed that our regulations governing workplace non-common areas be moved to a separate 
rule section, in order to highlight new compliance time lines for workplace non-common areas.56
53 Id, § 255(e).
54 The Commission will undertake a separate proceeding concerning Section 255.
55 47 C.F.R §68.112(bXl).
  56 See Section 68.112(bX3) in Appendix C and NPRM at paras. 24 - 26. In NPRM Appendix 
B, Section 68.112(bX3) is listed as Sections 68.112(b)(l)(BHG)- For clarification, we have 
changed the numbers, lettering and grammar of the rules proposed in the NPRM to the rules in 
Appendix C attached hereto.
8260
24. The NPRM proposed that all non-common-area workplace telephones must be 
hearing aid compatible by January 1, 2000, except that telephones purchased between January 
1, 1985, through December 31, 1989 must be hearing aid compatible by January 1, 2005.57 
The NPRM also proposed that employers with fewer than fifteen employees would be 
generally exempt from coverage of the workplace non-common area rules.58 Finally, the 
NPRM proposed that all U.S. Government employers with fifteen or more employees would 
be subject to the workplace non-common area rules.59
(2) Comments
25. No commenter disputed the application of the HAC Act to workplace common 
areas, nor the moving of the rules governing non-common areas into a new section. 
Comments in opposition to workplace requirements were generally directed at the 
Commission's authority to require ajl workplace telephones to be hearing aid compatible, by 
extending workplace requirements to non-common area telephones.60 The Association of 
College and University Telecommunications Administrators (ACUTA) commented that the 
implementation time lines and the fifteen employee cutoff for non-common areas "strike a 
reasonable balance between the needs of persons with hearing disabilities and the burden of 
compliance on small employers."61 The U.S. General Services Administration (GSA), the 
agency vested with responsibility for acquiring telecommunications services for use of Federal 
Executive Agencies, also filed comments and reply comments expressing support for the 
proposed workplace rules. ABA, however, urges the Commission to "change or eliminate" 
the effective dates for workplace non-common area compliance, stating that "establishing a 
date does nothing to change the confidence of the public but will place a burden on 
employers to make sure that after an arbitrary date they are in compliance."62
(3) Discussion
57 NPRM at para. 24.
58 NPRM at 14. But see paras. 31-34, infia, for discussion of individual workstation 
requirements, which will apply regardless of the number of employees.
59 NPRM at para. 25.
60 Se£ paras. 7-13, supra, for discussion of Commission authority to require all workplace 
telephones to be hearing aid compatible.
61 ACUTA Comments at 1.
62 ABA Comments at 3.
8261
26. Based on the comments received, we adopt Section 68.112(b)(3)63 in its 
entirety, including the implementation time lines and the exemption for employers with fewer 
than fifteen employees from the rules governing telephones in workplace non-common areas. 
In the adopted rule, we define non-common areas as "all workplace areas that are not 
common areas," and we give as examples "private enclosed offices, open area individual work 
stations and mail rooms." We further conclude that U.S. Government employers must also 
comply with these rules. We do not agree with ABA that establishing a certain date for 
compliance places a burden on employers, if that date gives employers reasonable time to 
come into compliance. The dates set in these rules are the result of a negotiated rulemaking; 
the recommendations of the Committee reflected a careful balancing of the interests of all 
potentially affected by these rules, including large and small businesses and other employers. 
Consequently, we find that the compliance dates will give employers a reasonable period of 
time to comply. As noted below, our rules also establish a "rebuttable presumptibn" after the 
compliance dates whereby employers will only have to replace non-compliant telephones on a 
case-by-case basis.64 We believe that the public should have assurances that the majority of 
workplace telephones are hearing aid compatible by a certain date.
27. In calculating the number of "employees" for purposes of compliance with 
Section 68.112(bX3), the total employment force of an establishment, and not the number of 
employees an employer may have at a particular work site, should be the determining factor.65 
Furthermore, the terms "employer" and "employee" as used in our regulations have the same 
meaning as these terms in the Americans with Disabilities Act.66 We do not adopt, however, 
the ADA's exceptions to the term "employer." The mandate of the HAC Act, which requires 
that all "essential telephones" be made hearing aid compatible, is much broader than that of 
the ADA, and the HAC Act does not specify exceptions for any employers. The Committee 
felt strongly that no entity employing fifteen or more employees should be excluded from the 
definition of "employer."67 As a general matter, therefore, no entity employing fifteen or 
more employees, including U.S. Government agencies, will be exempt from workplace non-
63 See Section 68.112(b)(3) in Appendix C.
64 See paras. 35-39, infra.
65 NPRM at para. 25.
66 42 U.S.C. § 12111 defines "employee" as "an individual employed by an employer" and 
"employer" as "a person engaged in an industry affecting commerce who has 15 or more 
employees for each working day in each of 20 or more calendar weeks in the current or 
preceding calendar year, and any agent of such person."
67 HACNRC Report at 19.
8262
common area rules.68
b. No Retrofitting Requirements
(1) Comments
28. EEAC objects to the Commission's proposed workplace rules, claiming that the 
rules would require "wholesale retrofitting of all workplace telephones."69 FM contends that 
the Commission's proposed rulemaking would require an employer to purchase hearing aid 
compatible telephones to replace non-hearing aid compatible telephones even when there are 
no employees with a hearing impairment requesting this type of accommodation.70 NAD, 
however, argues that no such "wholesale retrofitting" would occur, and that the Commission's 
proposed rules are "lenient" and compliance time lines "generous."71 NAD also asserts that 
"the rules will in reality affect a very small number of telephones and businesses, and even 
these businesses should be able to fully convert to hearing aid compatible equipment during 
their normal telephone replacement cycle."72 ITTA also recognizes that the proposed 
workplace rules would not require retrofitting.73
(2) Discussion
29. We reiterate that our proposed workplace rules would not require across-the- 
board field testing or retrofitting of all workplace telephones for hearing aid compatibility. 
The HAC Act has required that all telephones manufactured or imported for use in the U.S. 
since August 1989 be hearing aid-compatible.74 In addition, the Committee determined that 
the average life-cycle for telephone acquisition and replacement was approximately seven years.75
68 The ADA exempts "the United States, a corporation wholly owned by the United States, 
or an Indian tribe; or a bona fide private membership club (other than a labor organization) that 
is exempt from taxation under section 501(c) of the Internal Revenue Code." 42 U.S.C. §12111.
69 EEAC Comments at 2.
70 FMI Comments at 2.
71 NAD Reply Comments at 5-6.
72 Id at 6.
73 ITTA Comments at 4.
74 47 U.S.C. § 610(b)(l)(B).
75 See NPRM at para. 15, fii. 26.
8263
30. Thus, by the years 2000 and 2005, when the proposed rules require that all 
non-common area workplace telephones be hearing aid compatible,76 most non-compliant 
phones will already have been replaced with hearing aid compatible phones during normal 
replacement cycles. Furthermore, even after the years 2000 and 2005, there will be no 
retrofitting requirements and employers will not be required to locate non-compliant 
telephones. Rather, there will be a "rebuttable presumption" that all workplace phones are 
hearing aid compatible.77 We agree with NAD that, given the normal replacement cycle and 
the rebuttable presumption, the number of workplace telephones subject to replacement will 
be very small.78
(1) Background
31. The NPRM proposed to generally exclude headsets from the definition of 
"emergency use phones," and thus from hearing aid compatibility requirements.79 The NPRM 
also proposed, however, that current Section 68.112(bXl)80, which requires hearing aid 
compatible telephones to be "made available to a hearing-impaired employee for use by the 
employee in his or her employment duty," be modified to (1) require employers to provide 
hearing aid compatible headsets to employees needing such headsets for their employment 
duties, and (2) require all employers, regardless of the number of employees, to comply with 
this provision.81
(2) Comments
32. Aeronautical Radio, Inc. (ARINC), a representative of the air transport industry 
(a major user of headset equipment) states that its "concerns have now been appropriately 
addressed by the FCC's rule modifications."82 ACUTA, and commenters representing 
individuals with hearing disabilities, agree that hearing aid compatible telephones and
76 See para. 24, supra.
77 See Appendix C, Rule 68.112 (bXIXD). See paras 35-39, infra, for discussion of the 
"rebuttable presumption."
78 NAD Reply Comments at 6.
79 NPRM at paras. 27-28.
80 Seg 47 C.F.R.§ 68.(bXl)-
81 NPRM at para, 27.
82 ARINC Comments at 3.
8264
headsets should be made available to an employee with a hearing disability regardless of the 
number of employees in a workplace.83 CUNA asserts that the requirement that an employee 
be provided with hearing aid compatible headset equipment for his or her employment duty is 
an "unnecessary repetition" of the requirements of Title I of the ADA.84 CUNA also states 
that it was "confused" to see that the under-fifteen exemption would not apply to individual 
workstation provisions.85 NFTB generally objects to the elimination of the under-fifteen 
exemption even for employee workstation requirements, citing it as an undesirable precedent 
for small businesses.86
(3) Discussion
33. We conclude that headset equipment should generally be exempt from hearing 
aid compatibility requirements.87 Headsets are generally an individualized, specialty-use item. 
We do not agree, however, with CUNA's assertion that requiring employers to provide 
individual headsets on an as-needed basis is unnecessary in light of the ADA. Title I of the 
ADA contains general language requiring reasonable accommodations that do not impose an 
undue hardship.88 Our rule,89 however, is specifically tailored to the particular needs of an 
employee with a hearing disability, and to that employee's need for access to a hearing aid 
compatible telephone, including to a headset that is hearing aid compatible. Our rule, unlike 
the ADA, also will apply to all employers, including those with fewer than fifteen employees, 
and to Executive branch agencies of the Federal Government. The ADA specifically states 
that it does not invalidate any other Federal laws which provide equal or greater protection to 
individuals with disabilities. The HAC Act, and our rules pursuant to it, are examples of 
protections that are greater than those afforded by the ADA.
34. We conclude that Section 68.1 ^(bXSXA),90 addressing individual workstation 
requirements, should be adopted in its entirety. All employers, regardless of the number of 
their employees, must provide hearing aid compatible telephones and headsets to employees
83 ACUTA Comments at 1-2.
84 CUNA Comments at 4.
85 CUNA Comments at 5.
86 NFIB Comments at 1.
87 See. Sections 68.112(b)(l), 68.112(b)(3), 68.112(b)(3XQ in Appendix C.
88 42 U.S.C. § 12201(b). Sge paras. 18-20, supra.
89 See § 68.112(b)(3)(A) in Appendix C.
90 See Section 68.112(bX3)(A) in Appendix C.
8265
who need such phones to perform their employment duties. We consider such telephones to 
be "essential telephones" within the meaning given the term in the HAC Act, both as 
telephones "provided for emergency use" and as telephones "frequently needed for use by 
persons using . . . hearing aids."91 We do not believe that adoption of this rule sets a harmful 
precedent for small businesses. Small businesses with fewer than fifteen employees will still 
enjoy a general exemption from workplace non-common area requirements, and will thus only 
have to provide hearing aid compatible telephones in workplace common areas and on an as- 
needed basis for employees with hearing disabilities.
d. Rebuttable Presumption
(1) Background
35. In recognition of the difficulties involved in tracing, testing and identifying 
existing telephone equipment for hearing aid compatibility, we proposed in the NPRM that 
there be a rebuttable presumption that, as of a certain date, every telephone in the workplace 
is hearing aid compatible.92 The rebuttable presumption would apply as of either January 1, 
2000 (for telephones purchased by employers prior to January 1, 1985 or after December 31, 
1989), or January 1, 2005 (for telephones purchased by employers between January 1, 1985 
and December 31, 1989). This presumption can be rebutted, on a telephone-by-telephone 
basis, by any person legitimately on the premises who makes an identification of a particular 
telephone as non-hearing aid compatible.93 Once such an identification is made, the employer 
will then have fifteen working days to replace the non-compliant telephone with a hearing aid 
compatible telephone.94
(2) Comments
36. Many commenters support the adoption -of a rebuttable presumption. ACUTA, 
for instance, comments that the rebuttable presumption is "more than fair" and that the 15-day 
requirement is also "adequate." ITTA believes that the rebuttable presumption approach is 
"far preferable to mandatory retrofitting."95 NFTB, on the other hand, asserts that the 15-day 
time line is too short, and urges the Commission to adopt the reasonable accommodation 
approach taken by the ADA, which requires employers to respond to an employee's request
91 47 U.S.C. § 610(bX4).
92 NPRM at para. 31. 
93 14
94 Id
95 ITTA Comments at 4.
8266
for accommodation within a "reasonable" period of time.96 Finally, a number of commenters, 
including ITTA, also urge the Commission to clarify that the rebuttable presumption does not 
permit third parties to enter the premises of an employer for the purpose of auditing or 
surveying the telephones for hearing aid compatibility.97
(3) Discussion
37. We conclude that Section 68.112(bX3)(B) should be adopted in its entirety.98 
As of January 1, 2000, or January 1, 2005, whichever is applicable,99 there shall be a 
rebuttable presumption that all workplace non-common area telephones are hearing aid 
compatible. This rebuttable presumption will relieve employers of the need to field-test and 
identify whether their telephones are hearing aid compatible.
38. We further conclude that Section 68.112(bX3)(B) of our rules creates no third- 
party right of entry onto the premises of employers. The person making the identification of 
a telephone as non-hearing aid compatible must be an individual present in the normal course 
of the establishment's business, legitimately on the premises as an employee or invitee of the 
establishment.
39. We also conclude that a fifteen-day replacement period is reasonable. The 
requirement does not apply to businesses with fewer than fifteen employees and is the 
outcome of a negotiated rulemaking process. In addition, the requirement will not go into 
effect until the years 2000 or 2005, Le., eleven to sixteen years after all telephones imported 
or manufactured for use in the United States were required to be hearing aid compatible. 
Finally, in any enforcement action for violation of the fifteen day requirement, the 
Commission will give substantial weight to a showing of (1) a good faith effort to comply 
and (2) any unusual technical difficulties concerning the telephone system involved or the 
replacement or installation of a hearing aid compatible telephone, so long as the employer 
demonstrates that it will come into compliance within a reasonable period of time. This 
approach should address the concerns express by NFTB.
e. Replacement and Newly Acquired Telephones
96 NFIB Comments at 2.
97 ITTA Comments at 5.
98 See Section 68.112(bX3)(B) in Appendix C.
99 Workplace telephones are required to be hearing aid compatible as of January 1, 2000, 
unless the establishment purchased the telephones between January 1, 1985 and December 31, 
1989, in which case the telephones must be hearing aid compatible by January 1, 2005. See 
para. 24, supra.
8267
(1) Background/Comments
40. Section 68.112(bX3XQ would require that all "newly acquired" telephones in 
the workplace be hearing aid compatible.100 For purposes of this Section, "newly acquired" 
was defined as new, refurbished or secondhand telephones, including telephones taken from 
an establishment's stored inventory.101 Section 68.112(b)(3)(D), however, makes an exception 
for telephones taken from stored inventories existing prior to the time of enactment of the 
rules in this Report and Order.102 In such instances, the establishment would only be 
required to replace the telephone with a hearing aid compatible telephone upon a bona fide 
request from an employee or invitee. The Commission received little specific comment on 
this area. ACUTA agrees with the proposed rule, as well as the separate treatment of 
telephones taken from existing stored inventory.103
(2) Discussion
41. We conclude that proposed Sections 68.112(b)(3)(C) and 68.112(bX3)P) 
should be adopted in their entirety.104 The replacement or acquisition of a telephone creates a 
natural opportunity to install a hearing aid compatible telephone. This natural replacement 
requirement imposes little burden on employers. We conclude, furthermore, that the limited 
exception for replacements from inventories existing prior to the enactment of these rules is 
necessary to prevent the undesirable result of whole inventories of telephones becoming 
obsolete.
f. Safe Harbor 
(1) Background
42. In light of the generous implementation time lines for hearing aid compatibility 
in the workplace, the NPRM proposed a "safe harbor" rule which would ensure that at least 
one designated hearing aid compatible telephone for emergency use is present on every floor 
of a workplace.105 The designated phone could be coin-operated, a common area telephone or 
any other designated wireline or wireless telephone, and the manner of designation and the
100 See Section 68.112(3XQ in Appendix C. See ajsfi NEEM at para. 32.
101 See NPRM at para. 36.
102 Id See also. Section 68.112(b)(3XD) in Appendix C.
103 ACUTA Comments at 2.
104 See Sections 68.112(bX3)(Q and 68.112(bX3)(D) in Appendix C.
105 NPRM at para, 39.
8268
definition of "floor" would be left to the employer's discretion.106
(2) Comments
43. The Commission received numerous comments regarding this proposed rule. 
While no commenter specifically objected to the provision of a "safe harbor" telephone, a 
number of commenters representing individuals with hearing and speech disabilities urge the 
Commission to specify what is meant by a workplace "floor." The National Association of 
the Deaf/National Center for Law and Deafness (NAD/NCLD), for example, states that a 
definition of "floor" should be "limited to a reasonable traveling distance for an individual 
who might be in search of a telephone."107 ASHA proposes that the safe harbor phones be 
"those phones nearest the emergency exits in buildings."108 SHHH recommends that "where a 
floor has more than two corridors, at a minimum the employer be required to provide one 
designated HAC phone per set of two corridors on each floor."109 Numerous commenters 
representing people with hearing disabilities also ask that the Commission adopt a signage 
requirement to ensure visual notification of the location of the safe harbor telephone.
44. Several industry commenters, however, urge the Commission not to define 
what constitutes a workplace "floor," and to leave the matter to the employer's good-faith 
discretion. ACUTA, for example, feels that the proposed rule "allows flexibility for various 
types of workplace settings."110 ITTA also filed reply comments specifically urging the 
Commission not to define "floor," arguing that such rule-making "puts the Commission in the 
business of policing compliance with a vague requirement."111
(3) Discussion
45. We conclude that the words "on every floor of in our proposed rule should be 
replaced with the words "within a reasonable and accessible distance for an individual 
searching for a telephone from any point in."112 Comments from all parties have persuaded us 
that the use of the word "floor" is inadequate. Any rule based on the presence of floors or
106 Id,
107 NAD/NCLD Comments at 3.
108 ASHA Comments at 7.
109 SHHH Comments at 2.
110 ACUTA Comments at 2.
111 ITTA Reply Comments at 7.
112 See Section 68.112(bX3)(EXi) in Appendix C.
8269
corridors would not take into account workplaces such as fairgrounds and amusement parks, 
for example. Also, limiting our rule to a one-per-floor basis will not provide reasonable 
access for persons who work in large, sprawling office complexes. Finally, we conclude that 
we do not need to adopt an additional signage requirement, as the proposed rule already 
requires that the safe harbor phone be "designated" as such.113
46. In revising the proposed rule, we believe mat we are preserving the intent of 
the Committee that the location of the "safe harbor" phone be largely left to the employer's 
discretioa114 In setting up safe harbor telephones, and in providing information designating 
the location of such telephones, employers should put themselves in the position of a person 
"in search of a telephone," and locate such phones to ensure the most effective workplace 
coverage. If it is appropriate for the type of building, employers should install at least one 
safe harbor telephone on every floor. Employers should ensure that such telephones are 
placed in accessible locations.
2. Confined Settings 
a. Background
47. The NPRM proposed that, for confined settings with fifty or more beds, the 
room telephones provided by the establishment must be hearing aid compatible within one 
year of the adoption of the proposed rules.115 Establishments with fewer than fifty beds will 
have two years from the date of adoption of the rules to ensure thai all room telephones are 
hearing aid compatible.116 "Confined settings" include rooms in hospitals, residential health 
care facilities, and convalescent homes, in which the residents are not able to come and go at 
their discretion.117
48. The NPRM did not propose a rebuttable presumption for confined settings, 
because the vulnerability of persons in such settings increases the need to ensure that all room 
telephones are hearing aid compatible.118 Furthermore, the NPRM proposed that all newly
113 NPRM at para. 39. Sge proposed 47 C.F.R. § 68.112(bXlXG).
114 HACNRC Report at 21-22.
115 NPRM at paras. 41-42.
116 14
117 47 C.F.R. § 68.112(bX3); NPRM at para. 41 n. 66.
118 Id. at para. 41.
8270
acquired and replacement telephones in confined settings be hearing aid compatible.119 The 
NPRM also proposed to exclude prisons from the definition of confined settings, and 
proposed that confined setting establishments would not be responsible for ensuring that 
telephones installed and maintained by a patient were hearing aid compatible.120
49. Finally, the NPRM also proposed a qualified exception for confined setting 
establishments which offer an alternative means for the patient or resident to signal a life- 
threatening emergency, provided that such alternative means is "available, working and monitored."121
b. Comments
50. The Commission received little comment on the proposed rules for confined 
settings. The American Health Care Association (AHCA), a member of the Negotiated 
Rulemaking Committee, in comments also endorsed by Care Providers of Minnesota (CPM), 
expresses general support for the Commission's proposed rules. ACUTA indicates that it 
believes that its affected members, i.e.. colleges and universities with medical facilities, will 
"be able to comply with the proposed rule without an unreasonable burden."122 LHH, 
however, urges the Commission not to exclude prisons from the definition of confined 
settings and states that "alternative means of signalling" do not always provide reasonable 
access in the event of an emergency.123
c. Discussion
51. We adopt the proposed rules for confined setting telephones, and we specify 
particular dates in order to provide more certainty for confined setting establishments.124 We 
specify November 1, 1997 as the date by which establishments with fifty or more beds must 
ensure that all room telephones are hearing aid compatible. Establishments with fewer than 
fifty beds will have until November 1, 1998 to comply with these rules. We recognize that 
residents and patients in confined settings are generally more vulnerable in the event of an 
emergency, especially if they are ill or of advanced age, and we find, therefore, that no 
rebuttable presumption should apply to confined settings. While we adopt the exception for
119 Id at para. 43.
120 Id. at paras. 44-45.
121 Id at para. 45.
122 ACUTA Comments at 2.
123 LHH Comments at 3.
124 See Section 68.112(bX5) in Appendix C.
8271
confined settings which provide "alternative means of signalling," we stress that any such 
alternative means must in fact provide-the resident or patient with an effective means of 
signalling personnel in the event of an emergency. In other words, the equipment must be 
monitored and kept in good working order.125
52. Finally, we conclude that prisons should not be included within our definition 
of "confined settings," in recognition of the unique telecommunications requirements faced by 
prisons. As prisons do not usually provide telephones in every room or cell, we do not think 
our confined settings rules can be feasibly applied to prisons.126 We note, however, that our 
workplace hearing aid compatibility rules would still apply to the workplaces of prison 
employees.127
3. Hotels and Motels 
a. Background
53. The Commission's rules currently require that at least ten percent of the rooms 
in a hotel or motel be "equipped to accommodate a hearing impaired customer."128 In the 
NPRM we proposed that at least twenty percent of all rooms in a hotel or motel be required 
to have a hearing aid compatible telephone as soon as the rules adopted in this Report and 
Order become effective.129 Under this proposal, hotels and motels with eighty or more guest 
rooms would further be required to ensure mat all guest room telephones are hearing aid 
compatible within two years of the effective date of these rules, and those with fewer than 
eighty guest rooms would have three years to ensure that all room telephones are hearing aid- 
compatible.130
54. The NPRM established a different compliance schedule for hotels and motels 
which use telephones purchased during the period January 1, 1985 through December 31,
125 See § 68.112(5XCXii) in Appendix C.
126 See NESM at para. 44. 3ee_al§Q_ HACNRC Report at 26.
127 Id See Part B (1), supra (Workplace Telephones).
128 47 C.F.R. § 68.112(bX5). This requirement was adopted in 1992 and was not suspended 
by the Commission's April 1993 Order. See Order. 8 FCC Red at 4958. See also NPRM at para. 
50.
129 NPRM at para. 50.
130 Id. at para. 48.
8272
1989.131 Such hotels and motels would be required to ensure that: (1) twenty percent of their 
guest room telephones are hearing aid compatible as of the effective date of these rules; (2) 
twenty-five percent of their room telephones are hearing aid compatible within three years of 
the effective date of these rules; and (3) all guest room telephones are hearing aid compatible 
before January 1, 2000 (for hotels and motels with eighty or more eighty rooms), or January 
1, 2003 (for hotels and motels with fewer than eighty rooms).132
55. The NPRM also proposed that, if a hotel or motel room is "renovated or newly 
constructed, or the telephone in a hotel or niotel room is replaced or substantially, internally 
repaired," the telephone in that room must be hearing aid compatible.133
b. Comments
56. The majority of commenters representing individuals with hearing disabilities 
support the proposed hotel and motel rules. The American Hotel and Motel Association 
(AHMA), which was a member of the Negotiated Rulemaking Committee and which 
represents over 10,000 hotels, motels and lodging properties, supported the consensus 
recommendations of the Committee, and did not consider the rules to be unduly burdensome. 
The Commission received informal comments from forty-two individual hotel owners, and 
three State hotel associations, stating that existing HAC telephones are adequate to meet 
demand and that the proposed rules are burdensome and unnecessary.134
c. Discussion
57. We find the argument that the proposed rules are burdensome and unnecessary 
to be without merit. Committee members representing organizations of individuals with 
hearing disabilities stated that there are often too few hotel and motel rooms currently with 
hearing aid compatible telephones for individuals with hearing disabilities. They stated that 
the demand for these rooms often exceeds the supply of available rooms, and that it is 
difficult to locate hotels and motels with adequate facilities to accommodate conferences for 
organizations representing persons with hearing disabilities.135
58. The installation of hearing aid compatible telephones in hotels and motels
at para. 51. 
132 14
133 NPRM at para. 49.
134 Many of these hotel and motel owners also argue that the proposed rules duplicate the 
requirements of the ADA. This argument is addressed in paras. 18-20, supra.
135 N£RMatpara.51.
8273
fulfills an important public safety function. The Committee found that travelers with hearing 
disabilities may be especially vulnerable in emergency situations in hotel settings, because 
they are alone and dependent upon room telephones. They may be unfamiliar with the floor 
plan of the hotel or motel where they are staying.136 In addition, the Committee pointed out 
that because travelers are transient, they have less opportunity to request changes in 
equipment than they would in more permanent settings, such as workplaces.137 The HAC Act, 
by ensuring that all telephones located where a person "may be isolated in the event of an 
emergency" are hearing aid compatible, ensures that such travelers will have access to the 
telephone network in life-threatening situations. Accordingly, we conclude that the proposed 
rules for hotel and motel telephones should be adopted as of the dates indicated below.138
59. Rather than requiring twenty percent of all hotel and motel room telephones to 
be hearing aid compatible as of the effective date of these rules, we conclude that the twenty 
percent threshold should be effective as of April 1, 1997. This will give hotel and motel 
owners a reasonable amount of time in which to meet the twenty percent threshold. Hotels 
and motels with eighty or more guest rooms must ensure that all room telephones are hearing 
aid compatible before November 1, 1998, and those with fewer than eighty guest rooms will 
have until November 1, 1999 to ensure that all room telephones are hearing aid compatible. 
We do modify the NPRM proposal for those hotels and motels which use telephones 
purchased during the period January 1, 1985, through December 31, 1989. The selection of 
the years 2000 and 2003 by the Committee was based on an assumed effective date for the 
proposed rules of late 1995.139 Since the actual effective date will be a year later, we have 
changed the two negotiated dates to the years 2001 and 2004. Thus, for this category of 
telephones, hotels and motels will be required to ensure that hearing aid compatible 
telephones are installed in (1) twenty percent of all guest rooms by April 1, 1997; (2) twenty- 
five percent of all guest rooms as of November 1, 1999; and (3) one hundred percent of all 
guest rooms by January 1, 2001 (for establishments with eighty or more guest rooms) or by 
January 1, 2004 (for establishments with fewer than eighty guest rooms).
4. Costs Of Compliance
60. Under Section 610(e), the Commission must consider the costs, as well as the 
benefits, of the proposed rules to all telephone users, including persons with and without 
hearing disabilities.140 In the NPRM. we solicited comment on the costs to establishments of
136 HACNRC Report at 28.
137 Id
138 See Section 68.112(b)(6) in Appendix C.
139 NPRM at para. 50 and page 49.
140 47 U.S.C. § 610 (e).
8274
providing hearing aid compatible telephones.141 Apart from comments on the costs of 
complying with new volume control rules,142 there was little formal comment on the costs of 
compliance, although several hotel owners expressed some concern about cost in their 
informal comments.143
61. We noted in the NPRM that in making its recommendations, the Committee 
weighed the costs and benefits to all telephone users, including to persons with and without 
hearing disabilities.144 Representatives of large and small purchasers of telephones described 
to the Committee both the cost and effort that would be incurred as a result of the 
recommended regulations. Representatives of persons with hearing disabilities described the 
difficulties persons with hearing disabilities now experience when telephones are not hearing 
aid-compatible. Consumer representatives also described the increased access to telephone 
service such persons would receive if the Committee's proposed regulations were 
implemented Representatives of equipment manufacturers and industry standards-setters 
reviewed for the Committee the cost and implementation issues posed by design, manufacture 
and distribution of equipment recommendations made by the Committee.
62 We conclude, as we did tentatively in the NPRM. that the costs involved will 
not be substantial and are significantly outweighed by the benefits to be achieved. The 
deadlines in the rules are intended to complement the telephone replacement cycle in the 
normal course of business. The Committee determined that the average useful life of a 
telephone in an establishment is seven years.145 Since almost all telephones imported or 
nianufactured for use in the United States have been hearing aid compatible since 1989, it is 
reasonable to conclude that the bulk of telephones in establishments are, by now, hearing aid 
compatible. The new rules give establishments at least an additional year, and in most cases 
several additional years, before compliance is required. The rebuttable presumption extends 
this grace period even further for workplaces. Hotels and motels which use telephones 
purchased January 1, 1985 through December 31, 1989 have until the year 2004 to make their 
guest room telephones one hundred percent hearing aid compatible.146 Since these rules build 
on the normal, voluntary cycle of telephone replacement by establishments, we conclude that
at paras. 26, 46 and 53.
142 See para, 70, infra.
143 See, e.g.. January 2, 1996, letter from the California Hotel and Motel Association. See 
also para 56, supra.
144 NPRM at para, 20.
145 HACNRC Report at 12; NPRM at para. 15.
146 See Section 68.112(6XCXiii) in Appendix C.
8275
the additional costs to establishments to comply will not be substantial, particularly in light of 
the many benefits users with hearing disabilities will receive from increased access to the 
telephone network.
C VOLUME CONTROL 
1. Background
63. In the fcJERM, we proposed that all newly acquired and replacement telephones 
in workplaces, confined settings and hotels and motels be required to have volume control.147 
We noted that volume control would help the many hearing aid wearers whose hearing aids 
are not equipped with an electro-magnetic coil, and other individuals with hearing disabilities 
who do not use hearing aids.148 To help ensure an adequate supply of volume control 
telephones, we proposed that, a year after adoption of our rules, all telephones manufactured 
or imported for use in the U.S. be required to have volume control.149
2. Requiring Volume Control 
a. Statutory Authority
(1) Comments
64. Three commenters contend that the Commission lacks statutory authority to 
require volume control.150 They argue that volume control is not mentioned in the HAC Act, 
and that requiring volume control goes beyond the mandate of that Act.151 The Committee 
concluded that the statutory definition of hearing aid compatibility is sufficiently broad to 
include volume control.152
(2) Discussion
65. We find that the Commission has authority under the HAC Act to require 
volume control. Section 610(a) gives the Commission a broad mandate to "establish such
147 NPRM at para. 55.
148 Id at para. 60.
149 14 at para. 68.
150 ABA Comments at 5; EEAC Comments at 9; FMI Comments at 3.
151 14
152 HACNRC Report at 14.
8276
regulations as are necessary to ensure reasonable access to telephone service by persons with 
impaired hearing."153 As discussed below, the volume control requirement is needed to ensure 
reasonable access to telephone service by many persons with hearing disabilities.154 
Furthermore, Section 610(b) states that the Commission shall require that all essential 
telephones, and all telephones manufactured or imported for use in the United States, provide 
an "internal means for effective use with hearing aids."155 The HAC Act thus defines hearing 
aid compatibility generically and does not limit such compatibility to the provision of an 
electro-magnetic coil. Both the House and Senate Reports on the HAC Act state that 
technologies other than the electro-magnetic coil are contemplated in the definition of hearing 
aid compatibility, and the Senate Report specifically mentions amplification, or volume 
control, as an alternative technology.156 Finally, Section 610(e) states that the Commission 
must ensure mat its regulations "encourage the use of currently available technology."157 
Volume control is a currently available technology that allows telephones to be effectively 
used by persons with hearing aids, and by other persons with hearing impairment who do not 
use hearing aids.158
b. Need for Volume Control Requirement 
(1) Comments
66. Groups representing people with hearing loss strongly support the need for 
volume control requirements.159 NAD/NCLD states that volume control would "make 
telephones accessible for a ... large portion of the American population who do not have full 
access at the present time."160 SHHH states that volume control would benefit: (1) 4.6 
million persons who wear hearing aids but who do not have telecoils, (2) 1.2 million persons 
who have significant hearing loss and thus need both a telecoil and volume control, and (3)
153 47 U.S.C. § 610(a).
154 See paras. 63-66, infra.
155 47 U.S.C. § 610(bXl).
156 H.R, Rep. No. 674, 100th Cong., 2d Sess. 12 (1988); S. Rep. No. 391, 100th Cong., 2nd 
Sess. 10 (1988).
157 47 U.S.C. § 610(e).
158 Id
159 See, SHHH Comments at 2, ASHA Comments at 2, PHSDS Comments at 1, HIA Comments at 2.
160 NAD/NCLD Comments at 4.
8277
22 million persons with hearing disabilities who do not use hearing aids.161 Other 
commenters state that the U.S. population is getting older, that by age of 65 more than sixty 
percent of people have significant hearing impairments, and that in the next 10 years, there 
will be 40 million Americans with hearing loss due to the aging of the population.162
67. Thomson Consumer Electronics (TCE),163 however, argues that a volume 
control manufacturing requirement is not justified because the market alone can provide an 
adequate supply of volume controlled telephones.164 As evidence, TCE states that at least 
fifteen major manufacturers currently provide volume control telephones. In addition, ABA 
states that our proposed volume control rules duplicate its obligation under the ADA,165 and 
some informal comments by hotel and motel owners and associations state that such entities 
currently have enough volume control telephones to satisfy demand and that volume control 
requirements for hotels and motels are unnecessary. The issues of ADA duplication and the 
supply of hearing aid compatible hotel and motel telephones are addressed at paras. 18 and 
57, spa.
(2) Discussion
68. The HAC Act requires that telephones manufactured or imported for use in the 
United States be hearing aid compatible.166 Since we are now including volume control 
within the definition of hearing aid compatible,167 it follows that a requirement for 
manufacturing telephones with volume control must be set.
69. The record indicates that the proposed volume control requirements will make 
telephones more accessible for a significant portion of the population, including hearing aid 
wearers and others with hearing impairments. Furthermore, we are not persuaded that market 
forces alone would supply volume controlled telephones in sufficient quantity to satisfy the 
needs of all establishments required to provide such telephones under Sections 68.6 and
161 SHHH Comments at 3. SHHH estimates that mere are 28 million Americans with hearing 
loss, and that, of these, 5.8 million use hearing aids, and that twenty percent of hearing aid users 
have hearing aids with telecoils. Id. at 2-3.
162 AGB Comments at 1; ASHA Comments at 5.
163 TCE is a manufacturer of General Electric and RCA telephone products.
164 TCE Comments at 1.
165 ABA Comments at 5
166 47 U.S.C. § 610(b).
167 3gg paras. 75-77 Ma.
8278
68.317.168 The difficulties establishments experienced in attempting to comply with the 
regulations we adopted in 1992 were,- in part, due to insufficient supply of complying 
equipment.169 In addition, a manufacturing requirement is necessary for the same reason that 
Congress originally imposed a manufacturing requirement for hearing aid compatible 
telephones.170 As stated in the Senate Report, "By imposing the responsibility for hearing aid 
compatibility at the time of manufacture rather than the time of installation, the law draws a 
clear line and places the burden for compliance on a smaller, and more organized, number of 
entities."171 A blanket manufacturing requirement also reduces confusion and increases the 
likelihood that a new or replaced telephone used in an emergency will have volume control.
c. Costs and Availability 
(1) Background/Comments
70. Under Section 610(e), the Commission must consider the costs, as well as the 
benefits, of the proposed rules to all telephone users, including persons with and without 
hearing disabilities.172 hi the NPRM we solicited comment on the effect of the proposed 
rules on the costs of volume controlled telephones to manufacturers and on the price and 
availability of such telephones to consumers.173
71. TCE states that under the proposed technical standard a volume control 
requirement would increase manufacturing costs between $.05 and $.10 per telephone unit.174 
TCE also states that the proposed volume control technical standard should be modified (see. 
infra, at para. 81), and that if that modification is adopted, the additional costs could range 
from $.50 to up to $1.00 per telephone.175 TCE also states that there would be "millions of 
dollars" in additional start-up costs resulting from the need to redesign circuitry and cabinetry, 
modify current models in development, re-engineer molds and circuit boards, and to change
168 See Sections 68.6 and 68.317, Appendix C.
169 NPRM at para. 5.
170 See 47 U.S.C. § 610(bXl)(B).
171 Senate Report at 4.
172 47 U.S.C. § 610 (e).
173 NPRM at para. 70.
174 TCE Comments at 4.
175 TCE Comments at 4-5.
8279
product literature and advertising.176
72. Organizations representing persons with hearing disabilities note that telephones 
with volume control appear to be widely available and- often cost no more at the retail level 
than telephones without volume control.177 ACUTA contends that making volume control 
mandatory will lower the average cost of each volume-controlled telephone, because the costs 
will be distributed across all telephones manufactured in the U.S.178
73. Informal comments by hotel and motel owners and associations argue that 
meeting the proposed volume control requirement would be costly. Most of these 
commenters erroneously believe that the proposed rules would require that in two or three 
years all hotel and motel telephones would have to have volume control. ABA, however, 
states that the record in the Committee Report and the NERM on volume control is 
nonexistent or insufficient for the purposes of adopting regulations. ABA states that there is 
no history of manufacturing capability or the cost of volume control, and little in the record 
which discusses the current or future availability of volume control telephones.179
(2) Discussion
74. In the NPRM we specifically requested comment on the potential added 
manufacturing and consumer costs that might be added due to a volume control 
requirement180 Based on a review of the record, we conclude that our proposed volume 
control rules will not impose significant additional costs on telephone users, manufacturers or 
the establishments required to provide volume control telephones. TCE was the only 
manufacturer to file comments on the cost issue. According to TCE, even with the minimum 
performance standard which we add to our proposed volume control standard (see, jufia, at 
para. 83), volume control will only add an additional $.50 to $1.00 per unit to manufacturing 
costs. This amount appears to be generally affordable by the average consumer. Even when 
the start-up costs are added, we believe the average cost per unit will remain affordable, 
because those start-up costs will be averaged across millions of production units.181 In 
addition, commenters indicate that volume control telephones are already produced by several 
manufacturers and that they often cost no more at the retail level than telephones without
176 14 at 5.
177 SHHH comments at 4. See also LHH Comments at 4.
178 ACUTA Comments at 3.
179 ABA Comments at 4; ITTA Comments at 6. 
180 EERMatpara.70.
181 See ACUTA Comments at 3.
8280
volume control. Finally, a principal manufacturers' representative, TTA, made no mention of 
additional costs in either its comments or its reply comments. We conclude that while cost is 
a factor to be considered, it is not such a major obstacle as to negate the benefits to be 
derived from requiring volume control.
75. Many of the comments on volume control costs from hotels and motels are 
based on the erroneous assumption that the commenters will be required to replace all 
telephones that do not have volume control with volume-controlled telephones. Under the 
proposed rules, however, an existing telephone that does not have volume control does not 
have to be replaced with a volume controlled telephone merely because the existing telephone 
does not have volume control. Volume control is required only for newly purchased 
telephones, or when an existing telephone is replaced for some reason other than the absence 
of volume control.182 Such a reason might be that the telephone does not have electro 
magnetic coil compatibility, or because the telephone does not work properly and must be 
replaced In such cases, the replacement telephone must have both electro-magnetic coil 
compatibility and volume control, See discussion of hotel and motel requirements at para. 55, 
supra. Finally, we conclude that as a result of the comments received in response to the 
NPRM the record on volume control costs and availability is sufficient for purposes of 
adopting volume control regulations.
3. Inclusion in Definition of Hearing Aid Compatibility 
a. Background/Comments
76. In the NPRM, we proposed that, for newly acquired and replacement 
telephones, the definition of hearing aid compatibility would be expanded to include both a 
volume control feature and electro-magnetic coil compatibility.183 We also proposed that 
existing sections of our rules that refer to electro-magnetic coil compatibility as "hearing aid 
compatibility" be modified, for clarification, to state "as defined in Section 68.316."184
77. In its comments, TLA. states that the Commission's proposal to define "hearing 
aid compatibility" under some circumstances as both electro-magnetic coil compatibility and 
as volume control is confusing. Accordingly, TIA suggests mat volume control be required 
pursuant to the general language of Section 610(a), rather than also including volume control 
in the definition of hearing aid compatibility.185 That section states that "[tjhe Commission 
shall establish such regulations as are necessary to ensure reasonable access to telephone
182 See Section 68.112(6XAXii) in Appendix C; see also NPRM at para. 56.
183 NPRM at para. 56. 
184 Sj*NERMatpara.78. 
185 TTA Comments at 5-6.
8281
service by persons with impaired hearing."186 
b. Discussion
78. We conclude that the goals of the HAC Act would be best served if volume 
control is included within the definition of "hearing aid compatibility."187 Under the HAC 
Act, "essential telephones" must be hearing aid compatible. Furthermore, hearing aid 
compatible is defined generically as an "internal means for effective use with hearing aids."188 
This definition is broadly written, to encompass many types of evolving technology, including 
volume control.189
79. One type of "essential telephones" is "telephones provided for emergency 
use,"190 and it is within the category of "telephones provided for emergency use" that 
telephones in workplaces, confined settings and hotels -and motels fall.191 Volume control, as 
a type of hearing aid compatibility, properly fells within the scope of the HAC Act, and may 
be required in telephones "provided for emergency use." We agree with TLA that volume 
control also may be required because it fells within the language at 47 U.S. C. § 610(a).192
80. For clarification, we also modify sections 64.607, 68.3, 68.4, 68.112(b)(4), 
68.112(c), 68.224, and 68.316 by identifying hearing aid compatibility with the words "as 
defined in Section 68.316."
4. Transition Period
a. Background/Comments
81. In the NPRH we proposed that manufacturers and importers be required to 
include volume control in all telephones made or imported for use in the United States one 
year after the adoption of the new rules. TCE, HA and ACUTA suggest that a one-year
186 47 U.S.C. § 610(a).
187 See Sections 68.112(bX3XCXii), 68.112(bX5)(BXii), 68.112(b)(6XAXii).
188 47 U.S.C § 610(bXl).
189 See para. 7, supra.
190 47 U.S.C. § 610(bX4).
191 NPRM at para. 16.
192 "The Commission shall establish such regulations as are necessary to ensure reasonable 
access to telephone service by persons with impaired hearing."
8282
transition period until volume control manufacturing is required is too brief. HA states that a 
longer period is needed to redesign, test and evaluate products, to change printed materials, 
and to allow for an orderly depletion of existing non-volume-controlled telephones.193 TIA 
surveyed some of its members, who stated that an appropriate preparation period could range 
from six months to three years. LHH, however, argues that a one year phase in period is 
"more than generous," considering that the technology is not only readily available, but also 
currently widely used.194
b. Discussion
82. We conclude that two years would be a more appropriate transition time before 
manufacturers and importers are required to provide volume control telephones, because 
several commenters familiar with manufacturing procedures state that a one year period would 
be too brief a time to allow for equipment conversion and distribution changes. We note 
that a typical transition time for requiring the introduction of new technology under Part 68 is 
eighteen months.195 We have decided to allow a slightly longer than average transition period 
in this case because we are requiring a significant change in the features for virtually all 
telephones that will be imported or manufactured for use in the United States. Manufacturers 
and importers will be required to make this change by November 1, 1998.196
5. Technical Standard 
a. Background
83. In the NPRM, we proposed a technical standard for volume control based on 
the standard used by the Architectural and Transportation Barriers Compliance Board 
(ATBCB) for public telephones.197 The proposed standard applies a weighted average of 
loudness across the frequency range of a telephone's voice frequency band.198 This standard 
has been shown to correlate well with human perception of the loudness of speech on a 
telephone connection.199 The proposed standard uses Receive Objective Loudness Rating
193 TIA Comments at 9.
194 LHH Comments at 4.
195 See, £,& 47 C.F.R. §§ 68.2(e).
196 See Section 68.6 in Appendix C. 
197 NERMatpara,62. 
198 14 at para 63. 
199 Id at para. 63.
8283
(ROLR) to measure dB-gain, which is a numerical rating for loudness. This method of rating 
voice loudness has been used in the telecommunications industry for many years and the 
calculation procedures have been standardized.200
b. Feasibility of Volume Control Standard
(1) Comments
84. TCE states that the proposed standard needs a setting for a minimum 
performance level, because otherwise a manufacturer could technically meet the 12 dB to 18 
dB gain requirements by adding a lower volume setting rather than offering capability for 
higher volume.201 TIA agrees that a manufacturer could be in literal compliance with the gain 
requirement by lowering the volume setting, since the standard does not specify the nominal 
volume of sound that can emanate from a handset receiver. TIA states, however, that there is 
a voluntary industry standard for a minimum performance level that is working effectively, 
and that should rnanufacturers circumvent the spirit of'the proposed standard, the Commission 
could take steps to remedy the situation at that time.202
85. TCE also contends that the network-supplied current through the telephone line 
may be insufficient to power terminal volume control units; that high gain units may impact 
network performance and require a waiver of return loss and/or acoustical feedback 
performance specifications; and that safety may be jeopardized because Peak Acoustical 
Power safety requirements203 may be more difficult to meet. In response, TIA asserts its 
engineering committees have had no problems with the implementation of the 12 dB - 18 dB 
gain requirement in telephones powered from the telephone line. TIA also states that a high 
volume waiver is not needed, because the proposed standard calls for meeting relevant 
parameters at nominal volume, not at high volume. TIA also states that manufacturers will 
continue to comply with Peak Acoustic Power safety requirements, even at higher volumes.204
200 14; TFEE (Institute of Electrical and Electronics Engineers) Standard 661-1979 (R1992), 
"Method for Determining Objective Loudness Ratings of Telephone Connections."
201 TIA Reply Comments at 3-4.
202 TIA Reply Comments at 3-4.
203 Peak Acoustical Power safety requirements are limits prescribed by industry on the 
loudness of sound that can be projected through a receiver, to protect the ear drum from, for 
example, the sudden sound of electrical pulses caused by lightening.
204 TIA Reply Comments at 4.
8284
HA also adds, in an ex parte communication,205 that the standard as proposed in the NPRM 
applies only to analog telephones, and that separate paragraphs are needed to cover digital 
Integrated Services Digital Network (ISDN) telephones.206
(2) Discussion
86. The technical standard we adopt applies a standard of increasing loudness, or 
volume, that we intend be applied to a baseline normal volume setting, or level of volume set 
in a receiver.207 As proposed in the NPRJvf- the standard technically could be met by 
lowering the baseline volume setting in the receiver, and then applying the standard to the 
lowered volume setting, so that the level of loudness would increase, but not to a degree 
sufficiently useful to a telephone user with hearing disabilities. To avoid this possibility, we 
modify the standard in the NPRM by adding a requirement that the telephone also shall 
comply with the upper and lower limits for ROLR given in ANSI/HA-470-1987.208 To 
clarify the standard, we separate a portion of proposed Section 68.317(c) and make it into a 
new paragraph (f), and we make proposed subparagraph (d) into subparagraph (g).209 To 
include digital telephones210 within our standard, we add new paragraphs Section 68.317(c)
205 HA Ex Parte Communication, letter dated and filed April 30, 1996, from Roberta 
Breeden, TIA Director of Technical and Regulatory Affairs, to William Caton, Acting Secretary, 
Federal Communications Commissioa
206 For a discussion of ISDN telephones, see In the Matter of Petition to Amend Part 68 of 
the Commission's Rules to Include Terminal Equipment Connected to Basic Rate Access Service 
Provided via Integrated Services Digital Network Access Technology, and hi the Matter of 
Petition to Amend Part 68 of the Commission's Rules to Include Terminal Equipment Connected 
to Public Switch Digital Service, Report and Order. CC Docket No. 93-268, RM 7815, RM 6147, 
FCC 96-1, Adopted January 11, 1996, Released March 7, 1996 at para. 6. (ISDN R&Q)
207 See Section 68.317 in Appendix C.
208 See Section 68.317(a) in Appendix C; see also TIA ex parte letter dated April 24, 1996, 
filed April 25, 1996, from Roberta Breeden, TIA Director of Technical and Regulatory Affairs, 
to William Caton, Acting Secretary of the Federal Communications Commission (April 24, 1996 
Ex Parte). ANSI refers to the American National Standards Institute and EIA refers to the 
Electronic Industries Association. ANSI/EIA/TIA standards are available through the American 
National Standards Institute, Sales Department, 11 West 42nd Street, 13th Floor, New York, NY 
10036, (212) 642-4900.
209 See April 24, 1996 Ex Parte.
210 See ISDN R&O at para. 6.
8285
and (d), and we incorporate by reference paragraph 4.3.2 of ANSI/EJA/ITA-579-1991.211 We 
also amend NPRM proposed Sections 68.317 (a), (b), (c) and (d) to reflect the coverage of 
digital as well as analog telephones.
87. HA also states that the industry experience is that the standard works with 
line-powered units, and that a high volume waiver is not needed. We accept these statements 
of industry experience as reasonably predictive of what will occur when the volume control 
standard becomes part of our rules. We also accept TIA's statement that manufacturers will 
do what is necessary to meet the Peak Acoustic Power safety requirements.
c. Modifications to Technical Standard 
(1) Comments
88. TLA points out that the proposed standard incorrectly describes Receive 
Objective Loudness Rating (ROLR) as a rating system for expressing all "receive response,"212 
while ROLR is really only a measure of perceived loudness for a given input signal, which is 
a subset of the parameters that define receive response. To clarify the rule, TLA suggests 
adding the following footnote to subparagraph (a) of final rule Section 68.317:
Paragraph 4.1.2 of ANSI/ELA-470-A-1987 identifies several 
characteristics related to the receive response of a telephone. It 
is only the change in ROLR as a function of the volume control 
setting that is relevant to the specification of gain as required by 
this Section.
89. TLA also states that information requested in the NPRM to simulate the length 
of cable that will be used in measuring ROLR is still being developed by the industry. In the 
interim, TLA suggests that the Commission include in its final rules the information attached 
to its comments, namely a diagram of a loop simulator for 26 AWG cable.213
211 See paragraph 4.3.2 of ANSI/EIA/TIA-579-1991 in Appendix C. Paragraph 4.3.2 of 
ANSJ7ELA/TIA-579-1991 incorporates, by reference, two additional standards (LEEE Standard 
TERR 661-1979; Section 7.4 of LEEE Standard TERR 269-1992), and Section 7.4 of LEEE 269- 
1992 incorporates by reference Section 6.4.2 and Figures 12b and 13b of LEEE 269-1992. 
Section 6.4.2 refers to Figure 7 of TERR 269-1992. We also include these standards and figures 
in Appendix C. LEEE standards are available at the American National Standards Institute 
(ANSI), Sales Department, 11 West 42nd Street, 13th Floor, New York, NY 10036, (212) 642- 
4900.
212 TLA Comments at 4, citing NPRM at paragraph 63 and note 101.
213 See TLA Comments, Exhibit A
8286
90. In the NPRM, we proposed that the Commission delegate to the Chief, 
Common Carrier Bureau, the authority to issue a public notice of minor changes in the 
volume control standard HA supports this proposal, but adds that the referenced standards 
should not be restricted to ANSI standards.214
(2) Discussion
91. We accept HA's clarification of ROLR, and we adopt the suggested clarifying 
statement as a note to Section 68.317, rather than as a footnote. We will issue a final rule 
Section 68.117 that includes the suggested diagram (Loop Simulator for 26 AWG Cable) as 
part of the rule, as the Figure A referred to in Section 68.117(b).215 In addition, we note that 
industry standards are periodically updated. To help ensure that our rules continue to reflect 
the current industry standard, we delegate to the Chief, Common Carrier Bureau, the authority 
to make minor changes, pursuant to the Administrative Procedure Act,216 to the technical 
standards specified in Sections 68.316 and 68.317, in Order to incorporate minor changes 
made in the relevant industry standards.
e. Miscellaneous Issues
(1) Location of Volume Control Mechanism
92. In the NPRM, we requested comment on whether the volume control 
mechanism could be located in the network as well as in the terminal equipment.217 
Several commenters objected to the possibility of locating the volume control mechanism in 
the telephone network. The United States Telephone Association (USTA) and USWest 
contend that network-based volume control is technically infeasible and that existing handset 
control technology is effective.218 TLA argues that the best way to administer volume control 
under Part 68 is through regulating the terminal equipment that must be registered under Part 
68, such as a telephone, or a PBX that includes the accompanying telephones as part of its 
registratioa219 Based on the comments received, we will not require at this time that a 
volume control mechanism be located in the network.
214 HA Comments at 7; NPRM at paras. 64 and 71.
215 See Section 68.317 in Appendix C.
216 47 U.S.C. § 551-559.
217 NPRM at para. 72.
218 USTA Comments at 1; USWest Comments at 3.
219 TTA Comments at 7. See aj§o_ 47 U.S.C. § 68.300(b).
8287
(2) Volume Control in Speaker Phones
93. ASHA urges that the volume control requirement apply not only to the sound 
emanating from the handset or headset, but also to sound emanating from open speakers in 
the terminal base, commonly known as "speaker phones."220 TIA, however, states that there 
is no industry standard for measuring the loudness of sound emanating from a speaker phone, 
and that such standards will not be available for some time.221 We will not extend the 
volume control standard to "speaker phones" because the industry does not yet have the 
necessary standards for speaker phones. Furthermore, the focus of the Committee was on 
sound emanating from handsets and headsets, because it is sound from these portions of the 
terminal that relate most directly to the capabilities and efficacy of a hearing aid.
(3) Feedback
94. In the NPRM we noted that some individuals with hearing aids encounter 
problems of "feedback" between their hearing aid and the telephone receiver.222 Feedback 
occurs because both telephones and hearing aids contain microphones and amplifiers, and the 
electronic signals of these instruments can conflict and cause a characteristic feedback 
noise.223 LHH and HIA state that as long as the user can control the volume on a telephone, 
there should be little or no problem of feedback.224 Accordingly, we conclude that the 
addition of volume control will not create significant new problems of feedback between 
telephone receivers and hearing aids.
(4) Additional Proposed Modifications
95. HIA also proposes as "technical corrections" changing ROLR to RLR (Receive 
Loudness Rating) and substituting an international standard for the United States standard, 
ANSI/EIA 410-A-87.225 TIA asserts that the international standard places more emphasis on 
the low frequency portion of the telephone band, whereas the United States standard
220 ASHA Comments at 3.
221 TIA Reply Comments at 2.
222 NPRM at para. 66.
223 Ii
224 LHH Comments at 4; HIA Comments at 3.
225 HIA Comments at 4.
8288
encourages equal levels of gain to be applied across the entire frequency range.226 We 
conclude that we should not rename a working industry-developed concept and acronym by 
shortening ROLR to RLR, nor should we adopt an international volume control standard that 
is less suitable than the United States standard for the goals of our volume control rules.
96. HIA requests that the Commission define the increase in the magnetic field that 
will result from the increased volume due to volume control. HIA notes that this increase 
will affect the operation of hearing aid telecoils and make the telecoils more effective.227 TIA 
argues that the Commission should not attempt to quantify this magnetic field increase at this 
time because substantial additional work would need to be done by the appropriate industry 
standards committees to express the magnetic field requirements in a manner consistent with 
the standards of ROLR.228 We find that it is not essential to our rules to quantify the 
magnetic field increase at this time, and that we should not seek to quantify this increase until 
the industry standards committees have completed their work. We do encourage, however, 
continued dialogue between the telecommunications and hearing impaired equipment 
industries toward the development of voluntary standards for the increase in the magnetic 
field when volume is increased
(5) Obsolescence of Current Volume Control Telephones
97. One commenter expressed concern that establishing a volume control technical 
standard would render current volume control telephones obsolete.229 We acknowledge that 
the volume control mechanism in some existing volume controlled telephones will not be 
consistent with the technical standard we are adopting in this proceeding.230 These 
telephones, therefore, cannot be used as replacement telephones. Telephones that do not meet 
the new standard cannot be used as replacement telephones where a complying volume 
controlled telephone is required We note, however, that many existing volume controlled 
telephones will be in compliance with this standard
D. EQUIPMENT LABELING 
1. Background
98. Pursuant to Section 68.300(b) telephone equipment manufacturers are required
226 TIA Reply Comments at 5-6.
227 HIA Comments at 3.
228 TIA Reply Comments at 5.
229 California Hotel and Motel Association Comments at 1.
230 See Section 68.317 in Appendix C.
8289
to stamp equipment with either a date of manufacture or a serial number.231 In the NPRM we 
proposed that manufacturers be required to stamp registered terminal equipment and registered 
protective circuitry with a date of manufacture.23.2 We tentatively concluded that this change 
would make it easier for an establishment to determine whether its telephones are hearing aid 
compatible, because virtually all wireline telephones manufactured or imported for use in the 
United States after August 16, 1989 are required to be compatible with hearing aid 
telecoils.233 In addition, users would be able to determine if a telephone has volume control 
by the date of manufacture, once a volume control date-of-manufacture requirement is 
adopted. We did solicit comment, however, on whether, as an alternative, we should require 
manufacturers to stamp or emboss a symbol or set of letters, such as "HAC," on terminal 
equipment, in addition to, or as an alternative to, the date of manufacture.234
2. Comments
99. Several organizations representing persons with hearing disabilities comment 
that letters, a sign or a symbol would be more useful to the informed user than a date of 
manufacture because most telephone consumers are not aware of the significance of August 
16, 1989.235 Most commenters suggest using the letters "HAC" or "HAC/VC." Pursuant to 
the Paperwork Reduction Act,236 The Office of Management and Budget (OMB) disapproved 
the Commission's application for permission to change Section 68.300(b), because labeling 
equipment with dates would be meaningless to installers or users. Instead, OMB suggests 
the Commission could require labeling that would inform a user that the telephone is hearing 
aid compatible and equipped with volume control.
100. In its comments, TLA favors the use of date of manufacture over the use of 
signs or symbols. The use of the date has been an option in the Commission's Part 68 rules 
for years, TIA states, and manufacturers are familiar with using a date. TLA contends that 
stamping a telephone with the letters "HAC" might imply to the uninformed user that 
telephones without the "HAC" stamp are not hearing aid compatible, when, in fact, the vast 
majority of telephones in use are hearing aid compatible, because they were imported or 
manufactured after August 16, 1989.
231 47 C.F.R. § 68.300(bX3).
232 NPRM at paras. 29 and 73.
233 47 U.S.C. § 610(bXl)(B).
234 xTor>\/f 74
235 See e^g. LHH Comments at 5; TDI Comments at 2; NAD/NCLD Comments at 5; SHHH 
Comments at 6.
236 Paperwork Reduction Act of 1995, Pub. L. 104-13.
8290
3. Discussion
101. We concur with the statements of OMB and organizations representing persons 
with hearing disabilities that an easily recognizable symbol or set of letters would be more 
useful to the average telephone user than a date of manufacture. The average telephone user 
is not likely to know the significance of August 16, 1989, for electro-magnetic coil 
compatibility, and might more easily understand a set of letters or a recognizable sign or 
symbol.
102. In light of the record, we amend our proposal to require telephones with 
electro-magnetic coil compatibility to be stamped with the letters "HAC."237 We understand 
this is a commonly used term in organizations representing persons with hearing disabilities, 
and can be understood by the general public. We give rnanufacturers and importers six 
months, until April 1, 1997, before they are required to comply with this requirement.238 We 
also conclude that a separate set of letters is not needed to designate the presence of a volume 
control feature, because such a feature is generally apparent from the volume controls on a 
telephone. We will designate in our final rule that the letters "HAC" will indicate hearing aid 
compatibility as defined by Section 68.316 of our rules, L£., electro-magnetic coil 
compatibility. We also leave unchanged Section 68.300(bX3), which requires manufacturers 
to attach either a date of manufacture or a serial number.239 To the extent manufacturers do 
stamp equipment with the date of manufacture, and to the extent users and installers are 
familiar with the key dates for hearing aid compatibility and volume control, we conclude that 
providing the date of manufacture will be meaningful to installers and users.
E. CONSUMER EDUCATION 
3. Background/Comments
103. In the NPRMj. we sought comment on certain recommendations of the 
Negotiated Rulemaking Committee concerning consumer education.240 The Committee 
recommended that the Commission (1) issue a press release, hold a press conference about 
the Committee's Report and distribute the Report electronically; (2) develop a consumer 
information package about the hearing aid compatibility rules; (3) encourage the development
237 See Section 68.300(c) in Appendix C. We create a new subsection (c) so that the lettering 
requirement applies only to telephones, and not to the registered protective circuitry included in 
Section 68.300(b).
238 14
239 See 47 C.F.R § 68.300(bX3).
240 NPRM at para. 75.
8291
of information that could be included with hearing aid packaging; and (4) encourage 
voluntary public signage to identify the location of hearing aid compatible telephones in the 
workplace.241 We further noted in the NPRM that we had already completed the first 
recommendation of the Committee, namely to distribute the Committee Report electronically, 
to hold a press conference, and issue a press release regarding that Report.242
104. Numerous commenters strongly encourage the Commission to adopt consumer 
education initiatives.243 Some commenters suggest that the Commission should develop 
information packages for businesses and consumers.244 SHHH suggests that other initiatives 
such as a video on telecoils and Commission articles in consumer publications be 
considered.245 SHHH and LHH provide a list of items which can be included in hearing aid 
packaging, such as a description of the telecoil option, an overview of the HAC Act and 
Commission rules, and instructions on how to use telecoils.246 HA, a representative of 
hearing aid manufacturers, states that individual hearing aid manufacturers should be allowed 
to develop package inserts relevant to their products.247
b. Discussion
105. We recognize the importance of public education about hearing aid 
compatibility. Accordingly, we will issue a press release on this order* and make this order 
available electronically.248 Within six months of the adoption of this Report and Order, we 
will (1) develop "fact sheets" for consumers and businesses about hearing aid compatibility; 
(2) develop a "model" package insert for hearing aid manufacturers; and (3) coordinate with 
other government agencies and with private organizations in the development and 
dissemination of these materials. We agree with HIA, however, that the development of 
package inserts should be left largely to the individual hearing aid manufacturers, and we note 
that the use of any "model" developed by the Commission is not mandatory, but rather is
241
242 14 at para. 76.
243 ACUTA Comments at 4; ITTA Comments at 6; LHH Comments at 5; NAD/NCLD 
Comments at 5-6; SHHH Comments at 7-8.
244 See e^g, ACUTA Comments at 4.
245 SHHH Comments at 7-8.
246 SHHH Comments at 6; League Comments at 5:
247 HIA Comments at 4.
The Commission's Internet Home Page is currently located at http://www.fcc.gov.248
8292
provided for purposes of establishing a guideline. These efforts will give industry, 
government, individuals who have hearing disabilities and the general public ample notice of 
the effect of these rules on the rights and responsibilities of all parties concerned.
IV. CONCLUSION
106. We believe that the rules adopted in this Report and Order will significantly 
increase access to the telephone network for individuals with hearing disabilities, at minimal 
cost to workplaces, confined settings, hotels and motels and manufacturers. Hie rules 
represent the culmination of an extraordinary effort among organizations representing 
government, business, industry and individuals with hearing disabilities on the Committee. 
The efforts of this Committee produced consensus recommendations for Commission rules 
that strike a balance among the interests of the various interested parties. As a result of the 
Committee's efforts, the mlemaking process was streamlined: the Committee reached full 
consensus on all issues in record time, the number of comments in the record was greatly 
reduced and the public interest has been served.
V. REGULATORY FLEXIBILITY ACT ANALYSIS
107. Final Regulatory Analysis: Pursuant to the Regulatory Flexibility Act of 1980, 
5 U.S.C. Section 601, el seq.. the Commission's final analysis in this Report and Order is 
attached as Appendix B.
VL ORDERING CLAUSES
108. Accordingly, IT IS ORDERED that, pursuant to Sections 1, 4, 201-205, 218, 
220 and 610 of the Communications Act of 1934, as amended, 47 U.S.C. §§ 151, 154, 201- 
205, 218, 220, and 610, and 5 U.S.C. §§ 552 and 553; this Report and Order IS ADOPTED, 
and Parts 64 and 68 of the Commission's Rules ARE AMENDED as set forth in the attached 
Appendix C.
109. IT IS FURTHER ORDERED that the rule amendments set forth in Appendix C 
SHALL BE EFFECTIVE seventy days after publication in the Federal Register.
110. IT IS FURTHER ORDERED that the Emergency Request to Reinstate 
Enforcement of the Hearing Aid Compatibility Rules, dated May 12, 1993, by Alexander 
Graham Bell Association for the Deaf, et al, IS DISMISSED.
111. IT IS FURTHER ORDERED that, pursuant to Section 5(c)(l) of the 
Communications Act of 1934, as amended, 47 U.S.C. § 155(c)(l), authority is delegated to 
the Chief, Common Carrier Bureau, to make minor changes, pursuant to the Administrative 
Procedure Act procedures, in the technical standards specified in Sections 68.316 and 68.317 
of the rules, in order to incorporate minor changes made in the relevant industry standards.
8293
FEDERAL COMMUNICATIONS COMMISSION
William F. Caton 
Acting Secretary
8294
APPENDIX A: LIST OF PARTIES
L Parties Filing Comments (January 29,1996)*
Aeronautical Radio, Inc. (ARINC) 
Alexander Graham Bell Association for the Deaf (AGB) 
American Bankers Association (ABA) 
American Health Care Association (AHCA) 
The American Speech-Language-Hearing Association (ASHA) 
The Association of College and University Telecommunications Administrators, Inc. 
(ACUTA)
Care Providers of Minnesota (CPM) 
Center for the Deaf and Hard of Hearing (CDHH) 
Chicago Hearing Society (CHS) 
Communications Workers of America (CWA) 
Credit Union National Association, Inc.(CUNA) 
Equal Employment Advisory Council (EEAC) 
Food Marketing Institute (FMI) 
General Services Administration (GSA) 
HANDS Organization (HANDS) 
Hearing Industries Association (HIA) 
IMPACT, Inc., CEL (Center for Independent Living) 
The Information Technology and Telecommunications Association (ITTA) 
League for the Hard of Hearing (LHH)
The National Association of the Deaf and the National Center for Law and Deafness 
(NAD/NCLD)
National Association of Manufacturers (NAM) __ 
National Federation of Independent Business (NFIB) 
Newspaper Association of America (NAA) 
Pittsburgh Hearing Speech & Deaf Services, Inc (PHSDS). 
Self Help for Hard of Hearing People, Inc. (SHHH) 
Telecommunications for the Deaf, Inc. (TDD)
Telecommunications Industry Association User Premises Equipment Division (TIA); (Errata 
filed on February 27, 1996) 
Thomson Consumer Electronics (TCE) 
Ms. Bea Tusiani
United States Telephone Association (USTA) 
U S WEST, Inc. (USWest)
* Forty-five informal comment letters also were filed. Forty-two of the letters were from 
hotel and motel associations or individual hotels and motels.
8295
IL Parties Filing Reply Comments (February 29,1996)
American Public Communications Council (APCC)
Communications Workers of America (CWA)
General Services Administration (GSA)
Information Technology and Telecommunications Association (ITTA)
National Association of the Dea£ fit ai (NAD)
Telecommunications Industry Association (TIA)
8296
APPENDIX B: FINAL REGULATORY FLEXEBBLITY ANALYSIS
1. Final Regulatory Analysis: As required by Section 603 of the Regulatory 
Flexibility Act, 5 U.S.C. § 603 (RFA), an Initial Regulatory Flexibility Analysis (IRFA) was 
incorporated in the Notice of Proposed Rulemaking (NPRM).249 The Commission sought 
written public comments on the proposals in the NPRM. including on the IRFA The 
Commission's Final Regulatory Flexibility Analysis (FRFA)250 in this Report and Order is as 
follows:
a. Need for, and Objectives of, This action: This Report and Order amends the 
Commission's rules to require that eventually all wireline telephones in workplaces, confined 
settings and hotels and motels be hearing aid compatible and have volume control. The 
Report and Order also requires that as of November 1, 1998 all wireline telephones 
manufactured or imported for use in the United States must have volume control. These 
actions are needed to provide greater access to the telephone network by persons with hearing 
disabilities, pursuant to the jequirements of the Hearing Aid Compatibility Act of 1988 (HAC 
Act).251 The HAC Act directs the Commission to take affirmative and specific steps to 
increase such access.252 The objectives of these rules are to provide the needed greater 
access, while at the same time balancing the needs of establishments that must provide the 
hearing aid compatible and volume control telephones.
b. Summary of Significant Issues, Pfljf^ed by the Public Comments In Response to 
the Initial Regulatory Flexibility Analysis: There were no comments submitted in direct 
response to the Regulatory Flexibility Analysis in the NPRM. In general comments on the 
NPRH however, a number of cornmenters raised issues that might affect small entities. 
Several cornmenters stated that the Commission's proposed rules would duplicate the 
provisions of the Americans With Disabilities Act of 1990 (ADA), or exceed the 
Commission's authority under the HAC Act, thus unnecessarily burdening establishments.253 
A number of hotel and motel owners said the costs to replace telephones would be
249 Access to Telecommunications Equipment and Services by Persons With Disabilities, 
Notice of Proposed Rulemaking. 11 FCC Red 4338 (1995).
250 Our final analysis conforms to the RFA, as amended by the Contract With America 
Advancement Act of 1996, P.L. No. 104-121, 110 Stat. 847 (1996) (CWAAA). Subtitle II of 
CWAAA is "The Small Business Regulatory Enforcement Fairness Act of 1996" (SBREFA).
251 47 U.S.C. § 610(a).
252 See 47 U.S.C. § 710(a), (b).
253 See paras. 7-22, supra.
8297
burdensome.254 One manufacturer said the volume control manufacturing requirement could 
cost "millions of dollars" in start-up costs.255 An association of manufacturers stated that the 
proposed one-year phase-in of the volume control rnanufacturing requirement was too short.256 
Several organizations representing persons with hearing disabilities said that stamping the 
letters "HAC" on a telephone would be more informative than stamping the date of 
manufacture.257
c. Description and Estimate of Number of Small Businesses to Which Rules Will 
Apply:
(1) The RFA generally defines the term "small business" as having the 
same meaning as the term "small business concern" under the Small Business Act, 15 U.S.C. 
§ 632. A small business concern is one which (1) is independently owned and operated; (2) 
is not dominant in its field of operation; and (3) satisfies any additional criteria established by 
the Small Business Administration (SBA). Id. The RFA SBREFA provisions also apply to 
nonprofit organizations and to governmental organizations.
(2) The rules in this Report and Order apply to four industry categories: 
(a) workplaces; (b) confined settings, such as hospitals and nursing homes; (c) hotels and 
motels; and (d) importers and manufacturers of telephones for use in the United States. There 
is little overlap among these categories because the Commission's workplace rules affect 
workplace noncommon areas, while the rules that apply to confined settings and hotels and 
motels affect other than the workplaces of those establishments. Telephone manufecturers 
would be affected as workplaces, but separately affected by the requirement to affix the 
letters "HAC" to telephones and by the volume control manufacturing requirement. The 
determination of whether or not an entity within these industry groups is small is made by the 
Small Business Administration (SBA). These standards also apply in determining whether an 
entity is a small business for purposes of the RFA
(3) Workplaces: Workplaces encompass establishments for profit and 
nonprofit, plus local, state and federal governmental entities. Establishments with fewer than 
fifteen employees generally would be excluded, because they are exempt from the
254 See para. 56, spa.
255 See paras. 70-75, supra.
256 See para. 81, supra.
257 See paras. 98-102, supra.
8298
Commission's new rules,258 except for the work station requirement259 SBA guidelines260 to 
the SBREFA state that about 99.7 percent of all firms are small and have fewer than 500 
employees and less than $25 million in sales or assets. There are approximately 6.3 million 
establishments in the SBA database. We estimate that our rules would affect fewer than 6.3 
million establishments, because our rules exclude establishments with fewer than fifteen 
employees. However, we have not been able to determine what portion of the 6.3 million 
establishments have fewer than fifteen employees. The SBA data base does include nonprofit 
establishments, but it does not include governmental entities. SBREFA requires us to 
estimate the number of such entities with populations of less than 50,000 that would be 
affected by our new rules.261 There are 85,006 governmental entities in the nation.262 This 
number includes such entities as states, counties, cities, utility districts and school districts. 
There are no figures available on what portion of this number has populations of fewer than 
50,000. However, this number includes 38,978 counties, cities and towns, and of those, 
37,566, or 96 percent, have populations of fewer than SOjOOO.263 The Census Bureau 
estimates that this ratio is approximately accurate for all governmental entities. Thus, of the 
85,006 governmental entities, we estimate that 96 percent, or 81,600, are small entities that 
would be affected by our rules.
(4) Confined Settings: According to the SBA's regulations, nursing homes 
and hospitals must have annual gross receipts of $5 million or less in order to qualify as a 
small business concern. 13 C.F.R. §121.201. There are approximately 11,471 nursing care 
firms in the nation, of which 7,953 have annual gross receipts of $5 million or less.264 There 
are approximately 3,856 hospital firms in the nation, of which 294 have gross receipts of $5 
million or less. Thus, the approximate number of small confined setting entities to which the 
Commission's new rules will apply is 8,247.
258 The Commission adopted the ADA cutoff of exempting establishments with fewer than 
fifteen employees. See para, 27, supra: NPRM at para. 25.
259 See para. 31, supra.
260 A Guide to the Regulatory Flexibility Act, U.S. Small Business Administration, 
Washington D.C., May, 1996, at page 14.
261 RFA at Section 601(5).
262 1992 Census of Governments, Bureau of the Census, U.S. Department of Commerce.
263 Id
264 See Small Business Administration Tabulation File, SBA Size Standards Table 2C, 
January 23, 1996, SBA, Standard Industrial Code (SIC) categories 8050 (Nursing and Personal 
Care Facilities) and 8060 (Hospitals). (SBA Tabulation File)
8299
(5) Hotels and Motels: According to the SBA's regulations, hotels and 
motels must have annual gross receipts of $5 million or less in order to qualify as a small 
business concern. 13 C.F.R. §121.201. There are approximately 34,671 hotel and motel 
firms in the United States. Of those, approximately 31,382 have gross receipts of $5 million or less.265
(6) Telephone Manufacturers and Importers: According to the SBA's 
regulations, telephone apparatus firms must have 1,000 or fewer employees in order to qualify 
as a small business concern. 13 C.F.R. §l2l.201.266 There are approximately 456 telephone 
apparatus firms in the nation.267 Figures are not available on how many of these firms have 
1,000 or fewer employees, but 401 of the firms have 500 or fewer employees.268 It is 
probable that the great bulk of the 456 firms have 1,000 or fewer employees, and would be 
classified as small entities. In addition to telephone apparatus firms, there are approximately 
12,654 wholesale electronic parts and equipment firms in the nation. Many of these firms 
serve as importers of telephones.269 According to the SBA's regulations, wholesale electronic 
parts and equipment firms must have 100 or fewer employees in order to qualify as a small 
business entity. 13 C.F.R. §121.201. Of the 12,654 firms, 12,161 have fewer than 100 
employees, and would be classified as small entities.270
d. Description of Projected Reporting, Recordkeeping and Other Compliance 
Requirements of the Rules:
(1) Reporting and Recordkeeping: This Report and Order involves three 
reporting requirements. First, as of April 1, 1997, importers and manufacturers of telephones 
for use in the United States must stamp their telephones with the letters "HAC."271 The 
potential respondents to this requirement are importers and manufactures of telephones for use
265 SBA Tabulation File, SIC category 7010.
266 No foreign entity submitted comments on the NPRMf nor have we been able to obtain 
data on foreign telephone equipment manufacturers from other sources. The SBA does not 
compile data on foreign rnanufacturers.
267 U.S. Dept. of Commerce, 1992 Census of Transportation. Communications and Utilities 
(issued May 1995), SIC category 3661.
268 j^
269 U.S. Dept. of Commerce, 1992 Census of Transportation. Communications and Utilities 
(issued May 1995), SIC category 5065.
270 LL
271 See Section 68.300, Appendix C; see alsQ paras. 98-102,
8300
in the United States. Second, until the rules for all workplace telephones go into effect, 
employers are required to designate certain hearing aid compatible telephones for emergency 
use.272 The potential respondents to this requirement are owners of workplaces with fifteen or 
more employees. Third, a Commission rule regarding packaging is amended to clarify that 
the type of hearing aid compatibility referred to is electro-magnetic coil compatibility.273 The 
potential respondents to this requirement are importers and manirfacturers of telephones for 
use in the United States.
(2) Other Compliance Requirements:
(a) The rules adopted in this Report and Order require that as of certain 
dates, owners of workplaces, confined settings and hotels and motels provide telephones that 
have electro-magnetic coil hearing aid compatibility and volume control.274 These 
requirements will affect owners of workplaces, confined settings, and hotels and motels.
(b) The rules also require importers and manufecturers of telephones for use 
in the United States to provide telephones with volume control, beginning November 1, 
1998.275 These rules would affect small as well as large domestic manufacturers of 
telephones.
e. Commission Efforts to Learn Ofr and Respond To, the Views of Small 
Business: In 1992 the Commission adopted rules requiring hearing aid compatible 
telephones in workplaces, confined settings and hotels and motels.276 As the time to 
implement the rules approached, businesses, including small businesses, stated that they were 
having difficulty implementing the rules.277 In response, the Commission suspended the rules 
in 1993.278 Subsequently, the Commission formed the nineteen-member Hearing Aid 
Compatibility Negotiated Rulemaking Committee. Among the Committee's membership 
were representatives of small business. Both the hotel and motel representatives (American 
Hotel and Motel Association) and the confined setting representatives (American Health Care 
Association) have many small members. In addition, the Tele-Communications Association
272 See Section 68.112(bX3)(E) in Appendix C; see aJsa paras. 42-46, supra.
273 See Section 68.224 in Appendix C.
274 See Section 68.112(b) in Appendix C.
275 See Section 68.6 in Appendix C; see' also para. 82, supra
276 See paras. 2-6, supra: NPRM at paras. 4-9.
277 See NPRM at para. 5.
278 LL
8301
(now known as The Information Technology and Telecommunications Association, or 
ITTA),279 a broadly based end-users group, was a member. ITTA has approximately 1,000 
members, including small entities as members.280
f. Commission Efforts to Minimize Burdens on Small Business:
(1) In applying the new rules, the Commission has sought to minimize any 
disproportionate burden on small entities. The workplace requirements, for example, 
generally exempt workplaces of fewer than fifteen employees. The Commission provided this 
exemption because small employers have smaller budgets, which can make installation of new 
telephones disproportionately more burdensome for those employers.281 This is the same 
coverage cutoff standard used in the ADA,282 In calculating the number of "employees" for 
purposes of compliance, the total employment force of an establishment, not the number of 
employees an employer may have at a particular site, is the determining factor. This 
distinction emphasizes that it is the overall size of the entity, not the circumstance of the 
deployment of its employees, that determines the impact of the Commission's requirements.283
(2) The Commission also took into account the needs of small entities in 
setting the compliance deadlines for workplaces. The Committee determined that the average 
useful life of a workplace telephone is seven years. Almost all telephones manufactured or 
imported for use in the United States since August 16, 1989 have had to be hearing aid 
compatible. Thus, at the present time, any workplace telephone is most likely to be hearing 
aid compatible. As a margin of flexibility, however, the Commission set the workplace 
compliance deadline for November 1, 2005 for telephones purchased between January 1, 1985 
through December 31, 1989, and November 1, 2000 for all other telephones.284 Even after 
those dates, small entities are allowed to exercise the rebuttable presumption, so that they do 
not have to test and replace their telephones.285 Before those dates, workplaces may use
279 See para. 3, supra.
280 Id 
281 Se£NJBEMatpara.25.
282 Id
283 See para. 27, supra.
284 See para. 24, supra.
2851 See Final Rules, Appendix C; see also para 35, supra. The presumption is that beginning 
January 1,2000 (or 2005, depending on when the telephones were purchased), an employer may 
presume its workplace telephones are hearing aid compatible. The presumption can be rebutted 
on a telephone-by-telephone basis by any person legitimately on the workplace premises who
8302
existing stored telephone inventories as replacements, subject to a rebuttable presumption.286 
Thus, the stored inventories of small entities are not rendered obsolete.
(3) The requirements for confined settings and hotels and motels also make 
distinctions in the size of establishment. Smaller establishments are given more time to 
comply. Confined setting establishments with fewer than fifty beds are given an extra year, 
until November 1, 1998, to comply, and hotels and motels with fewer than eighty rooms also 
are given an extra year, until November 1, 1999, to comply.287
(4) The Commission also took into account the needs of small entities in 
the terms of the volume control manufecturing requirement. The Commission had proposed, 
in the NPRM a one-year deadline for this requirement, but after receiving comment from 
organizations representing large and small manufacturers, the Commission extended the 
period to two-years, until November 1, 1998, before compliance with the volume control rule 
is required. Similarly, the requirement that manufacturers affix the letters "HAC" to new 
telephones does not go into effect upon the effective date of the new rules, but six months 
later, on April 1, 1997.288 Current small manufacturer telephone inventories are not affected 
by this requirement.
(5) Under Section 610(e) of the HAC Act, the Commission must consider 
the costs, as well as the benefits, of the proposed rules to all telephone users, including 
persons with and without hearing disabilities.289 In the NPRM. the Commission solicited 
comment on the costs to establishments of providing volume control and hearing aid 
compatible telephones.290 After reviewing the comments, the Conimission concluded that the 
new rules will not impose significant additional costs on telephone users, manufacturers or 
establishments, and that any costs are significantly outweighed by the benefits to be achieved.291
g. Commission Efforts to Maximize Benefits: Small entities will be among the
makes an identification of a particular telephone as not being hearing aid compatible. Id. 
286 See Section 68.112(bXl)(F) in Appendix C. 
287 14
288 Id,
289 47 U.S.C. § 610 (e).
290 NPRM at paras. 26, 46 and 53.
291 See paras. 62 and 74-75, supra.
8303
beneficiaries of the Commission's new rules. Under the new rules, telephones in workplaces, 
confined settings and hotels and motels will be more accessible to persons with hearing 
disabilities. These changes may lead to new business for hotels and motels and confined 
settings, and workplaces may be able to hire better employees, since the pool of potential 
employees will be widened to include persons with hearing disabilities. In addition, the level 
of public safety will increase in all three settings, thereby benefitting both the business setting 
and the public at large. Telephones also will be easier to identify by installers, many of 
whom will be small entities, as hearing aid compatible, once they are stamped "HAC." 
Finally, the volume control requirement probably will increase the consumer demand for 
volume control telephones, benefitting large and small manufacturers alike.
h. Significant Alternatives Nflinipnj^ing Impact on SfrnaJl Entities That Were 
Rejected:
(1) The Commission considered not including within the purview of 
"telephones provided for emergency use" telephones in workplace non-common areas, 
telephones in confined settings and telephones in hotels and motels. However, the 
Commission concluded that given the nature of such settings, and the needs of persons in 
such settings, telephones in workplace noncommon areas, confined settings and hotels and 
motels should be considered telephones provided for emergency use. The Commission noted 
that persons with hearing disabilities are particularly vulnerable in confined settings and hotels 
and motels because the persons may be unfamiliar with the settings and isolated in the event 
of an emergency.
(2) Similarly, the Commission considered not adding a requirement for 
volume control, but concluded that volume control should be required. The HAC Act defines 
telephone hearing aid compatibility as "an internal means for effective use with hearing 
aids,"292 and the legislative history cites amplification, or volume control, as one such type of 
internal means.293 The Commission is obliged under the HAC Act to encourage the use of 
currently available technology in fulfilling the acfs mandates.294 Through the conclusions of 
its advisory committee, the Hearing Aid Compatibility Negotiated Rulemaking Committee, the 
Commission determined that volume control is a currently available technology that would 
help give many persons with hearing disabilities increased access to the telephone network.295
292 47 U.S.C. § 610
293 See para, 65, supra.
294 47 U.S.C. § 610(e).
295 See paras. 66-69, supra.
8304
i. Summary of Paperwork. Recordkeeping. and Other Compliance Requirements for 
Wireline Telephones:
(a) Paperwork requirements: As of April 1, 1997, importers and 
manufacturers of telephones for use in the United States must stamp their telephones with the 
letters "HAC." Until the rules for all workplace telephones go into effect, employers are 
required to designate certain hearing aid compatible telephones for emergency use. A 
Commission rule regarding packaging is amended to clarify that the type of hearing aid 
compatibility referred to is electro-magnetic coil compatibility.
(b) Recordkeeping requirements: NONE.
(c) Other compliance requirements:2^6
As of the effective date of this order, telephones, including headsets, 
made available to an employee with a hearing disability for use by that employee in his or 
her employment duty shall be hearing aid compatible;
As of the effective date of this order, newly purchased or replacement 
telephones in workplaces, confined settings and hotels and motels must be hearing aid 
compatible. In workplaces, if the replacement telephone is from inventory existing before the 
effective date of this order, any person may make a bona fide request that such telephone be 
hearing aid compatible, and, after November 1, 1998, have volume control.
As of the effective dale of this order, if a hotel or motel room is 
renovated or newly constructed, or the telephone in a hotel or motel room is replaced or 
substantially, internally repaired, the telephone must be hearing aid compatible.
As of the effective date of this order, and until the applicable workplace 
dates of January 1, 2000 or 2005, workplaces of fifteen or more employees must provide and 
designate telephones for emergency use by employees with hearing disabilities by providing a 
hearing aid compatible telephone within a reasonable and accessible distance for an individual 
searching for a telephone from any point in the workplace, or by providing hearing aid 
compatible wireless telephones.
As of April 1, 1997, the telephones in at least twenty percent of hotel 
and motel guest rooms must be hearing aid compatible.
As of November 1, 1997 telephones (except telephones purchased and
296 This summary represents only a general statement of requirements for establishments, 
manufacturers and importers. For a complete and particular statement, see the Final Rules in 
Appendix C.
8305
maintained by a resident for use in that resident's room, and except where a confined 
establishment has an alternate means of signalling life-threatening or emergency situations 
mat is available, working and monitored) in confined settings with fifty or more beds must be 
hearing aid compatible;
As of November 1, 1998, telephones (except telephones purchased and 
maintained by a resident for use in that resident's room, and except where a confined 
establishment has an alternate means of signalling life-threatening or emergency situations 
that is available, working and monitored) in confined settings with fewer than fifty beds must 
be hearing aid compatible;
As of November 1, 1998, the telephones in hotels and motels with 
eighty or more guest rooms must be hearing aid compatible;
As of November 1, 1998 telephones for use in the United States
provided by importers and manufacturers must have volume control, and newly purchased and 
replacement telephones in workplaces, confined settings and hotels and motels must have 
volume control. In addition, in hotels and motels, where a hotel or motel room is renovated 
or newly constructed, or the telephone is replaced or substantially, internally repaired, the 
telephone in that room must have volume control.
As of November 1, 1999, the telephones in hotels and motels with 
fewer than eighty guest rooms must be hearing aid compatible.
As of November 1, 1999, where a hotel or motel uses telephones
purchased during the period January 1, 1985 through December 31, 1989, the telephones in at 
least twenty-five percent of hotel and motel guest rooms must be hearing aid compatible.
As of January 1, 2000, non-common area telephones (except headsets, 
and except for telephones purchased between January 1, 1985 and December 31, 1989, and 
except for telephones made available to an employee with a hearing disability under Section 
68.112(bX3XA)) in workplace establishments of fifteen or more employees must be hearing 
aid compatible. There shall be a rebuttable presumption that, as of January 1, 2000, all such 
telephones located in the workplace are hearing aid compatible.
As of January 1, 2001, where a hotel or motel uses telephones
purchased during the period January 1, 1985 through December 31, 1989, the telephones in 
one hundred percent of hotel and motel guest rooms must be hearing aid compatible, if the 
hotel or motel has eighty or more guest rooms.
As of January 1, 2004, where a hotel or motel uses telephones
purchased during the period January 1, 1985 through December 31, 1989, the telephones in 
one hundred percent of hotel and motel guest rooms must be hearing aid compatible, if the 
hotel or motel has fewer than eighty guest rooms.
8306
As of January 1, 2005, non-common area telephones (except headsets, 
and except for telephones made available to an employee with a hearing disability under 
Section 68.112(b)(3XA)) purchased between January 1, 1985 and January 1, 1989 in 
workplace establishments of fifteen or more employees must be hearing aid compatible. 
There shall be a rebuttable presumption that, as of January 1, 2005, all such telephones 
located in the workplace are hearing aid compatible.
j. Report to Congress: The Secretary shall send a copy of this Final Regulatory 
Flexibility Analysis along with this Report and Order in a report to Congress pursuant to 
Section 251 of the Small Business Regulatory Enforcement Fairness Act of 1996, codified at 
5 U.S.C. Section 801(aXlXA). A copy of this RFA will also be published in the Federal 
Register.
8307
APPENDIX C: FINAL RULES
Part 64 of Title 47 of the Code of Federal Regulations is amended as follows: 
PART 64 - MISCELLANEOUS RULES RELATING TO COMMON CARRIERS
1. The authority citation for Part 64 continues to read as follows:
AUTHORITY: Sec. 4, 48 Stat 1066, as amended; 47 U.S.C. 154, unless otherwise noted. 
Interpret or apply sees. 201, 218, 226, 228, 48 Stat. 1070, as amended, 1077; 47 U.S.C. §§ 
201, 218, 226, 228, 610 unless otherwise noted.
2. Section 64.607 is amended to read as follows:
§ 64.607 Provision of hearing aid compatible telephones by exchange carriers
In the absence of alternative suppliers in an exchange area, an exchange carrier must 
provide a hearing aid compatible telephone, as defined in § 68.316, and provide related 
installation and maintenance services for such telephones on a detariffed basis to any 
customer with a hearing disability who requests such equipment or services.
Part 68 of Title 47 of the Code of Federal Regulations is amended as follows:
PART 68 - CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE 
NETWORK
1. The authority citation for Part 68 continues to read as follows:
AUTHORITY: Sees. 1, 4, 5, 201-5, 208, 215, 218, 226, 227, 303, 313, 314, 403, 404, 410, 
602 of the Communications Act of 1934, as amended, 47 U.S.C. §§ 151, 154, 155, 201-5, 
208, 215, 218, 226, 227, 303, 313, 314, 403, 404, 410, 602, 610.
2. Section 68.3 is amended by adding the following definition to the terms used in Part 
68:
*****
Hearing aid compatible: Except as used at §§ 68.4(a)(3) and 68.414 of these rules, 
the terms hearing aid compatible or hearing aid compatibility are used as defined in § 68.316, 
unless it is specifically stated that hearing aid compatibility volume control, as defined in § 
68.317, is intended or is included in the definition.
8308
3. Section 68.4 is amended to read as follows: 
§ 68.4 Hearing aid compatible telephones.
(aXl) Except for telephones used with public mobile services, telephones used with 
private radio services, and cordless and secure telephones, every telephone manufactured in 
the United States (other than for export) or imported for use in the United States after August 
16, 1989, must be hearing aid compatible, as defined in § 68.316. Every cordless telephone 
manufactured in the United States (other than for export) or imported into the United States 
after August 16, 1991, must be hearing aid compatible, as defined in § 68.316.
(2) Unless otherwise stated and except for telephones used with public mobile 
services, telephones used with private radio services and secure telephones, every telephone 
listed in § 68.112 must be hearing aid compatible, as defined in § 68.316.
4. A new Section 68.6 is added as follows: 
§ 68.6 Telephones with volume control.
As of November 1, 1998, all telephones, including cordless telephones, as defined in Section 
15.3(j) of these rules, manufactured in the United States (other than for export) or imported 
for use in the United States, must have volume control in accordance with Section 68.317 of 
these rules. Secure telephones, as defined by Section 68.3 of these rules, are exempt from 
this section, as are telephones used with public mobile services or private radio services.
5. Section 68.112 is amended by revising paragraphs (bXl), (b)(3), (bX4) and (b)(5), and 
by revising paragraph (c), to read as Sections (bX3), (bX5) and (bX6), respectively, as 
follows:
§68.112 Hearing Aid Compatibility
* * * *
(b) Emergency use telephones. Telephones "provided for emergency use" include the 
following:
(1) Telephones, except headsets, in places where a person with a hearing disability 
might be isolated in an emergency, including, but not limited to, elevators, highways, and 
tunnels for automobile, railway or subway, and workplace common areas. Note: Examples of 
workplace common areas include libraries, reception areas and similar locations where
8309
employees are reasonably expected to congregate.
(2) * * *
(3) Telephones, except headsets, in workplace non-common areas. Note: Examples 
of workplace non-common areas include private enclosed offices, open area individual work 
stations and mail rooms. Such non-common area telephones are required to be hearing aid 
compatible, as defined in Section 68.316, by January 1, 2000, except for (i) those telephones 
located in establishments with fewer than fifteen employees; and (ii) those telephones 
purchased between January 1, 1985 through December 31, 1989, which are not required to be 
hearing aid compatible, as defined in Section 68.316, until January 1, 2005.
(A) Telephones, including headsets, made available to an employee with a 
hearing disability for use by that employee in his or her employment duty, shall, however, be 
hearing aid compatible, as defined in Section 68.316.
(B) As of January 1, 2000 or January 1,. 2005, whichever date is applicable, 
there shall be a rebuttable presumption that all telephones located in the workplace are 
hearing aid compatible, as defined in Section 68.316. Any person who identifies a telephone 
as non-hearing aid-compatible, as defined in Section 68.316, may rebut this presumption. 
Such telephone must be replaced within fifteen working days with a hearing aid compatible 
telephone, as defined in Section 68.316, including, as of November 1, 1998, with volume 
control, as defined in Section 68.317.
(C) Telephones, not including headsets, except those headsets furnished under 
Section 68.112(bX3XA), that are purchased, or replaced with newly acquired telephones, must 
be:
(i) Hearing aid compatible, as defined in Section 68.316, after the 
effective date of Section 68.112(bX3);
(ii) Including, as of November 1,1998, with volume control, as defined 
in Section 68.317.
(D) When a telephone under Subsection (C) is replaced with a telephone from 
inventory existing before the effective date of amended Section 68.112(b)(3), any person may 
make a bona fide request that such telephone be hearing aid compatible, as defined in Section 
68.316. If the replacement occurs as of November 1, 1998, the telephone must have volume 
control, as defined in Section 68.317. The telephone shall be provided within fifteen working 
days.
(E) During the period from the effective date of amended Section 68.112(bX3) 
until the applicable date of January 1, 2000 or January 1, 2005, workplaces of fifteen or more 
employees also must provide and designate telephones for emergency use by employees with
8310
hearing disabilities through one or more of the following means:
(i) By having at least one coin-operated telephone, one common area 
telephone or one other designated hearing aid compatible telephone within a reasonable and 
accessible distance for an individual searching for a telephone from any point in the 
workplace; or
(ii) By providing wireless telephones that meet the definition for hearing 
aid compatible for wireline telephones, as defined in Section 68.316, for use by employees in 
their employment duty outside common areas and outside the offices of employees with 
hearing disabilities.
* * * * *
(4) All credit card operated telephones, whether located on public property or in a 
semipublic location (e.g. drugstore, gas station, private club), unless a hearing aid compatible 
(as defined in § 68.316) coin-operated telephone providing similar services is nearby and 
readily available. However, regardless of coin-operated telephone availability, all credit card 
operated telephones must be made hearing aid-compatible, as defined in § 68.316, when 
replaced, or by May 1, 1991, which ever comes sooner.
(5) Telephones needed to signal life threatening or emergency .situations in confined 
settings, including but not limited to, rooms in hospitals, residential health care facilities for 
senior citizens, and convalescent homes.
(A) A telephone that is hearing aid compatible, as defined in Section 68.316, 
is not required until:
(i) November 1, 1997, for establishments with fifty or more beds, 
unless replaced before that time; and
(ii) November 1, 1998, for all other establishments with fewer than 
fifty beds, unless replaced before that time.
(B) Telephones that are purchased, or replaced with newly acquired telephones, 
must be:
(i) Hearing aid compatible, as defined in Section 68.116, after the 
effective date of amended Section 68.112(t>X5);
(ii) Including, as of November 1, 1998, with volume control, as defined 
in Section 68.317.
8311
(C) Unless a telephone in a confined setting is replaced pursuant to Section 
68.112(bX5)(B), a hearing aid compatible telephone shall not be required if:
(i) A telephone is both purchased and maintained by a resident for use in that 
resident's room in the establishment; or
(ii) The confined setting has an alternative means of signalling life-threatening 
or emergency situations that is available, working and monitored
(6) Telephones in hotel and motel guest rooms, and in any other establishment open to 
the general public for the purpose of overnight accommodation for a fee. Such telephones are 
required to be hearing aid compatible, as defined in Section 68.316, except that, for 
establishments with eighty or more guest rooms, the telephones are not required to be hearing 
aid compatible, as defined in Section 68.316, until November 1, 1998; and for establishments 
with fewer than eighty guest rooms, the telephones are not required to be hearing aid 
compatible, as defined in Section 68.316, until November 1, 1999.
(A) Anytime after the effective date of amended Section 68.112(bX6), if a 
hotel or motel room is renovated or newly constructed, or the telephone in a hotel or motel 
room or is replaced or substantially, internally repaired, the telephone in that room must be:
(i) Hearing aid compatible, as defined in Section 68.316, after the 
effective date of amended Section 68.112(bX6);
(ii) Including, as of November 1, 1998, with volume control, as defined 
in Section 68.317.
(B) The telephones in at least twenty percent of the guest rooms in a hotel or 
motel must be hearing aid compatible, as defined in Section 68.316, as of April 1, 1997.
(C) Notwithstanding the requirements of Section 68.112(bX6), hotels and 
motels which use telephones purchased during the period January 1, 1985 through December 
31, 1989 may provide telephones that are hearing aid compatible, as defined in Section 
68.316, in guest rooms according to the following schedule:
(i) The telephones in at least twenty percent of the guest rooms in a 
hotel or motel must be hearing aid compatible, as defined in Section 68.316, as of April 1, 
1997;
(ii) The telephones in at least twenty-five percent of the guest rooms in 
a hotel or motel must be hearing aid compatible, as defined in Section 68.316, by November
8312
1, 1999; and
(iii) The telephones in one-hundred percent of the guest rooms in a 
hotel or motel must be hearing aid compatible, as defined in Section 68.316, by January 1, 
2001 for establishments with eighty or more guest rooms, and by January 1, 2004 for 
establishments with fewer than eighty guest rooms.
*****
(c) Telephones frequently needed by the hearing impaired. Closed circuit telephones, 
i.e., telephones which cannot directly access the public switched network, such as telephones 
located in lobbies of hotels or apartment buildings; telephones in stores which are used by 
patrons to order merchandise; telephones in public transportation terminals which are used to 
call taxis or to reserve rental automobiles, need not be hearing aid compatible, as defined in § 
68.316, until replaced.
*****
6. Section 68.224 is amended at subsection (a) to read as follows: 
§ 68.224 Notice of non-hearing aid compatibility.
Every non-hearing aid compatible telephone offered for sale to the public on or after 
August 17, 1989, whether previously-registered, newly registered or refurbished, shall:
(a) Contain in a conspicuous location on the surface of its packaging a statement that 
the telephone is not hearing aid compatible, as is defined in §§ 68.4(aX3) and 68.316 of these 
rules, or if offered for sale without a surrounding package, shall be affixed with a written 
statement that the telephone is not hearing aid-compatible, as defined in §§ 68.4(a)(3) and 
68.316 of these rules; and
0>)* * *
*****
7. Section 68.300 is amended by adding a new subsection (c) as follows:
§ 68.300 Labelling requirements.
*****
(c) As of April 1, 1997, all registered telephones, including cordless telephones, as defined in 
Section 15.30) of these rules, manufactured in the United States (other, than for export) or
8313
imparted for use in the United States, that are hearing aid compatible, as defined in Section 
68.316, shall have the letters "HAC" permanently affixed thereto. "Permanently affixed" shall 
be defined as in Section 68.300(bX5). Telephones used with public mobile services or private 
radio services, and secure telephones, as defined by Section 68.3 of these rules, are exempt 
from this requirement
* * * * *
8. Section 68.316 is amended in its title and its introductory paragraph to read as 
follows:
§ 68.316 Hearing aid compatibility magnetic field intensity requirements: technical 
standards.
A telephone handset is hearing aid compatible for the purposes of this section of Part 
68 if it complies with the following standard, published by the Telecommunications Industry 
Association, copyright 1983, and reproduced by permission of the Telecommunications 
Industry Association:
*****
9. A new Section 68.317 is added as follows:
§ 68317 Hearing aid compatibility volume control: technical standards.
(a) An analog telephone complies with the Commission's volume control requirements if the 
telephone is equipped with a receive volume control that provides, through the receiver in the 
handset grheadset of the telephone, 12 dB of gain minimum and up to 18 dB of gain 
maximum, when measured in terms of Receive Objective Loudness Rating (ROLR), as 
defined in paragraph 4.1.2 of ANSI/EIA-470-A-1987 (Telephone Instruments With Loop 
Signaling). The 12 dB of gain minimum must be achieved without significant clipping of 
the test signal. The telephone also shall comply with the upper and lower limits for ROLR 
given in Table 4.4 of ANSI/EIA-470-A-1987 when the receive volume control is set to its 
normal unamplified level.
Note: Paragraph 4.1.2 of ANSI/EIA470-A-1987 identifies several 
characteristics related to the receive response of a telephone. It is only the 
normal unamplified ROLR level and the change in ROLR as a function of the 
volume control setting that are relevant to the specification of volume control 
as required by this section.
(b) The ROLR of an analog telephone shall be determined over the frequency range from 300 
to 3300 HZ for short, average, and long loop conditions represented by 0, 2.7, and 4.6 km of 
26 AWG nonloaded cable, respectively. The specified length of cable will be simulated by a
8314
complex impedance. (See Figure A.) The input level to the cable simulator shall be -10 dB 
with respect to 1 V open circuit from a 900 ohm source.
(c) A digital telephone complies with the Commission's volume control requirements if the 
telephone is equipped with a receive volume control that provides, through the receiver of the 
handset or headset of the telephone, 12 dB of gain minimum and up to 18 dB of gain 
maximum, when measured in terms of Receive Objective Loudness Rating (ROLR), as 
defined in paragraph 4.3.2 of ANSI/EIA/nA-579-1991 (Acoustic-To-Digital and Digital-To- 
Acoustic Transmission Requirements for ISDN Terminals). The 12 dB of gain minimum 
must be achieved without significant clipping of the test signal. The telephone also shall 
comply with the limits on the range for ROLR given in paragraph 4.3.2.2 of ANSI/EIA/TIA- 
579-1991 when the receive volume control is set to its normal unamplified level.
(d) The ROLR of a digital telephone shall be determined over the frequency range from 300 
to 3300 Hz using the method described in paragraph 4.3.2.1 of ANSI/EL4/HA-579-1991. No 
variation in loop conditions is required for this measurement since the receive level of a 
digital telephone is independent of loop length.
(e)The ROLR for either an analog or digital telephone shall first be determined with the 
receive volume control at its normal unamplified level. The minimum volume control setting 
shall be used for this measurement unless the manufacturer identifies a different setting for 
the nominal volume level. The ROLR shall then be determined with the receive volume 
control at its maximum volume setting. Since ROLR is a loudness rating value expressed in 
dB of loss, more positive values of ROLR represent lower receive levels. Therefore, the 
ROLR value determined for the maximum volume control setting should be subtracted from 
that determined for the nominal volume control setting to determine compliance with the gain 
requirement
(f) The 18 dB of receive gain may be exceeded provided that the amplified receive capability 
automatically resets to nominal gain when the telephone is caused to pass through a proper 
on-hook transition in order to minimize the likelihood of damage to individuals with normal 
hearing.
(g) These incorporations by reference of paragraph 4.1.2 (including Table 4.4) of American 
National Standards Institute (ANSI) Standard ANSI/EIA-470-A-1987 and paragraph 4.3.2 of 
ANSI/ELA/TIA-579-1991 were approved by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 C. F. R Part 51. Copies of these publications may be purchased 
from the American National Standards Institute (ANSI), Sales Department, 11 West 42nd 
Street, 13th Floor, New York, NY 10036, (212) 642-4900. Copies also may be inspected 
during normal business hours at the following locations: Federal Communications 
Commission, 2000 M Street, N.W., Public Reference Room, Room 220, Washington, D.C. 
20554; and Office of the Federal Register, 800 N. Capitol Street, N.W., suite 700, 
Washington, D.C.
8315
R1
R2
~ C1
R3——»^WV-»-
R4
C2
C3
L1
-«———•-
C4
Component
R,.R4 
R2. R, 
C,,C4 
C2.C3 
L,,La
0.914 km (3 kft)
124 n
174 fl 
0.0113 nF 
0.0122 ».F 
0.336 mH
1.83km (6 kft)
249 Q 
312 il 
0.0226 nF 
0.0255 nF 
0.983 mH
Notes:
(1) All values are ±1%.
(2) 2.7 km (9 kft) and 4.6 km (15 kft) can be made up of 
cascaded sections of the above.
Loop Simulator for 26 AWG Cable
Figure A
8316
APPENDIX D: STANDARDS INCORPORATED BY REFERENCE
The following standards are incorporated by reference into final rule Section 68.317 in 
Appendix C. These standards are in addition to the incorporation by reference into Section 
68.317 of Paragraph 4.1.2 of ANSI/EIA-470-A-1987, provided in Appendix D to the Notice 
Of Proposed Rulemaking.
1) Paragraph 4.3.2 of ANSI/EIA/IIA-579-1991
Standard IEEE 661-1979 
3) Section 7.4 of IEEE Standard TFRR 269-1991
8317
ANSI/El A/Tl A-57 9-19 91 
APPROVED: FEBRUARY 20, 1991
EIA/TIA
STANDARD
ini
< ui Acoustic-To-Digital and 
Digital-To-Acoustic Transmission 
Requirements for ISDN Terminals
EIA/TIA-579
MARCH 1991
ELECTRONIC INDUSTRIES ASSOCIATION
ENGINEERING DEPARTMENT
8318
NOTICE
EIA/TTA Engineering Standards and Publications are designed to serve the public interest 
through eliminating misunderstandings between manufacturers and purchasers, facilitating 
interchangeability and improvement of products, and assisting the purchaser in selecting and 
obtaining with minimum delay the proper product for his particular need. Existence of such 
Standards and Publications shall not in any respect preclude any member or nonmember 
of EIA/TIA from manufacturing or selling products not conforming to such Standards and 
Publications, nor shall the existence of such Standards and Publications preclude their 
voluntary use by those other than EIA/TIA members, whether the standard is to be used 
either domestically or internationally.
Recommended Standards and Publications are adopted by EIA/TIA without regard to 
whether their adoption may involve patents on articles, materials, or processes. By such 
action, EIA/TIA does not assume any liability to any patent owner, nor does it assume any 
obligation whatever to parties adopting the Recommended Standard or Publication.
This EIA/TIA Standard is considered to have International Standardization implication, but 
the International Electrotechnical Commission activity has not progressed to the point where 
a valid comparison between the EIA/TIA Standard and the IEC document can be made.
This Standard does not purport to address all safety problems associated with its use or all 
applicable regulatory requirements. It is the responsibility of the user of this Standard to 
establish appropriate safety and health practices and to determine the applicability of 
regulatory limitations before its use.
(From Standards Proposal No. 1920-A, formulated under the cognizance of the TR-41.3 
Subcommittee on Telephones.)
Published by
ELECTRONIC INDUSTRIES ASSOCIATION
Engineering Department
2001 Pennsylvania Ave., N.W.
Washington, D.C. 20006
PRICE: Please refer to the current
Catalog of EIA & JEDEC STANDARDS & ENGINEERING PUBLICATIONS 
or call the EIA STANDARDS SALES DEPARTMENT (202/457-4966)
e TELECOMMUNICATIONS INDUSTRY ASSOCIATION 1991
All rights reserved 
Printed in U.S.A.
8319
EIA/TIA-579
ACQUSTIC.TQ.DIGTTAL AND DTGITAL-TQ.ArOUSTTr
TRANSMISSION REQUIREMENTS FOR ISDN
TERMINALS
TABLE OF CONTENTS
1. INTRODUCTION...........................................................................1
2. SCOPE........................................................................................2
3. DEFINITIONS..............................................................................^
4. TECHNICAL REQUIREMENTS.........................................................5
4.1 Frequency Response ...............................................................54.2 Noise and Distortion................................................................6
4.3 Objective Loudness Ratings....................................................... 84.4 Acoustic Echo Path Loss........................................................... 10
4.5 Peak Acoustic Pressure............................................................ 114.6 Feature for the Hearing Impaired................................................. 12
APPENDDCA- REFERENCES.............................................................15
APPENDKB- RATIONALE FOR NOISE AND DISTORTION...................... 16REQUIREMENTS
APPENDKC- RATIONALEFOR ACOUSTICECHO PATH........................ 17LOSS (AEPL) REQUIREMENTS
APPENDDCD- RATIONALEFOR TOLR AND ROLR.................................19REQUIREMENTS
8320
EWITA-579 PageS
4.2.4.2 Mcasuri?6"1 Method
The receive S/D ratio shall be measured using the test procedure described in Section 7.7.2 of TPP.F 269-1991. The digital telephone shall be placed in a 
quiet room with the transmitter isolated from sound input and mechanical 
disturbances.
Telephone sets with adjustable receive levels shall be adjusted so that their ROLR is as close as possible to the nominal value of section 4.3.2,2 for this 
test.
4.2.4.3 Requirement
The receive S/D ratio shall meet the following requirements:
Tone Input Level Minimum S/D Ratio dBmO dB
-2.5 to -32.5 30-42.5 24
-47.5 20
4.3 Objective Loudness Ratings
The rationale for the objective loudness rating requirements in this standard is contained in Appendix D.
4.3.1 Transmit Objective Loudness Raring
The TOLR for a digital telephone set is the conversion ratio of a defined acoustic signal at the mouth reference point to the transmit signal at the 
interface.
4.3.1.1 Measurement Method
The TOLR shall be calculated, in accordance with IEEE 661-1979 (Ref A3), 
from the transmit frequency response measured using Section 7.3 of IEEE 269-1991.
8321
ELVITA-579 Page 9
4.3.1.2 Requirement
The terminal should be designed to have a nominal TOLR value of -46 dB. The TOLR shall fall within the range -38 dB to -51 dB.
4.3.2 Receive Objective Loudness Raring
The ROLR for a digital telephone set is the conversion ratio of a defined digital signal at the receive input interface to an acoustic output signal from the 
receiver.
4.3.2.1 Measurement Method
The ROLR shall be calculated, in accordance with TF.F.F. 661-1979. from the receive frequency response measured using Section 7.4 of rEKF. 269-1991
4.3.2.2 Requirement
The terminal should be designed to have a nominal ROLR value of 51 dB. The ROLR shall fall within the range 46 dB to 56 dB. The range of ROLR 
values provided by terminals with adjustable receive levels may exceed these limits but should span the nominal level of 51 dB.
4.3.3 Sidetone Objective Loudness Rating
The sidetone objective loudness rating (SOLR) for a digital telephone set is the ratio of a defined input acoustic signal at the mouth reference point to the 
resulting acoustic output signal from the receiver.
4.3.3.1 Measurement Method
The SOLR shall be calculated, in accordance with IEEE 661-1979, from the sidetone frequency response measured using Section 7.5 of IEEE 269-1991.
Telephone sets with adjustable receive levels shall be adjusted so that their ROLR is as close as possible to the nominal value of section 4.3.2.2 for this 
test
4.3.3.2 Requirement 
The SOLR shall fall within the range 3 to 15 dB.
8322
,'AMWCAN NATIONAL]
ANSI/IEEE Std 661-1979
IEEE Standard Method for 
Determining Objective Loudness 
Ratings of Telephone Connections
ats
I
Ul
Published by The Institute of Electrical and Electronics Engineers. Inc. 345 East 47th Street New York, New York 10017 
Obtained from and reproduced by Global Engineering Oocurnents with the permission of IEEE under royatty agreement 
15 Inverness Way East, Englewood, Colorado 80112-&343JSA 303-792-2181 800454-7179
ANSI/IEEE Std 661-1979
An American National Standard
IEEE StandardMethod 
for Determining Objective Loudness 
Ratings of Telephone Connections
Sponsor 
Transmission Systems Committee
of the IEEE Communications 
Society
Approved June 16,1978 
IEEE Standards Board
Approved February 15,1983 
American National Standards Institute
© Copyright 1979 by
The Institute of Electrical and Electronics Engineers. Inc 
345 East 47th Street, New York, NY 10017, USA
No pan of this publication may be reproduced in any form,
in an electronic retrieval system or otherwise, 
without the prior written permission of the publisher.
8324
Approved June 16,1978 
IEEE Standards Board
Joseph L. Koepfinger, Chairman Irvin N. Howell, Jr, Vice Chairman
Ivan G. Eastern, Secretary
William E. Andrus Jay Forstcr Donald T. Michael
C. N. Bergiund Ralph I. Mauser Voss A. Moore
Edward J. Cohen Leering M. Johnson William S. Morgan
Warren H. Cook Irving Kolodny Robert L. Pritchard
David B. Dobson William R. Kruesi Blair A. Rowley
R. O. Duncan Thomas J. Martin Ralph M. Showers
Charles W. Flint John E. May B. W. Whit ting ton
8325
Foreword
(This Foreword is not a pan of IEEE Std 661-1979, Standard Method for Determining Objective Loudnen Ratings 
of Telephone Connections.)
This IEEE Standard Method for Determining Objective Loudness Ratings of Telephone Connec 
tions has been prepared in response to a need by the telecommunications industry for a standard 
method of testing transmission performance of partial and overall telephone connections in a man 
ner that reflects the attribute of subjective loudness. This document complements and is dependent 
on IEEE Std 269-1971, Standard Method for Measuring Transmission Performance of Telephone 
Sets. Individuals from private and government design, manufacturing, and research organizations 
have given freely of their time in preparing, testing, and reviewing this standard.
The IEEE will maintain this document current with the state of the technology. Comments, 
suggestions, and requests for interpretations should be addressed to:
Secretary
IEEE Standards Board
Institute of Electrical and Electronics Engineers
345 East 47th Street
New York,
New York 10017
This standard was prepared by the Subcommittee on Telephone Instrument Testing of the 
Transmission Systems Committee of the IEEE Communications Society. The members of the 
subcommittee are:
K. Simonson, Chairman E. S. Hineline, Jr, Secretary
F. T. Andrews M. J. Leach
L. A. Berry G. A. Ledbetter
C. F. Buster, Jr T. Lisbon
M. Chytil N. G. Long
J. F. Dunlap R. P. McCabe
J. B. Eppes A. Mankhrsky
R. P. Farrell D. J. Morgen
R. F. Foster L. Poradowski
A. S. Howeil L. A. Strommen
J. J. Jettt J. L. Sullivan
B. Katz C. G. Svala
8326
Contents
SECTION PAGE
1. Introduction ............................................................ 5
2. Scope and Purpose ....................................................... 6
3. Definitions ............................................................. 6
3.1 Loudness Rating.................................................... 6
3.2 Reference System ................................................... 6
3.3 Objective Loudness Rating (OLR)....................................... 7
3.4 Voltage and Pressure Levels............................................ 7
3.5 Overall Objective Loudriess Rating (OOLR) ............................... 7
3.6 Transmitting Objective Loudness Rating (TOLR)........................... 7
3.7 Receiving Objective Loudness Rating (ROLR) ............................. 7
3.8 Sidetone Objective Loudness Rating (SOLR) .............................. 7
3.9 Electrical Objective Loudness Rating (EOLR).............................. 7
3.10 Source/Load Impedance ...........................:.................. 7
3.11 Loudness Equation .................................................. 7
4. References.............................................................. 8
5. Instrumental Method...................................................... 8
5.1 General........................................................... 8
5.2 Test Equipment..................................................... 8
5.3 Measuring System ................................................... 10
5.4 Calibration ........................................................ 13
5.5 Test Procedure ..................................................... 13
6. Computational Method.................................................... 14
FIGURES
Fig 1 H-Pad Circuit. ...................................................... 10
Fig 2 Sending End of Measuring System....................................... 11
Fig 3 Receiving End of Measuring System ..................................... 11
Fig 4 A Measurement of Overall Objective Loudness Rating (OOLR); ..............
B Measurement of Transmitting Objective Loudness Rating (TOLR): ..........
C Measurement of Receiving Objective Loudness Rating (ROLR); ............
D  Measurement of Sidetone Objective Loudness Rating (SOLR); .............
E Measurement of Electrical Objective Loudness Rating (EOLR); ............ 12-13
Fig 5 Graphical Loudness Computation Form .................................. 15
TABLES
Table 1 Example of Computation of Transmitting Objective Loudness Rating ........... 16
Table 2 Example of Computation of Receiving Objective Loudness Rating. ............. 16
APPENDIXES
Appendix A Loudness Rating Method. ......................................... 17
Appendix B Weighted Acoustic Source Signal.................................... 19
Appendix C Weighted Electrical Source Signal................................... 20
APPENDIX FIGURES
Fig Al Computation of Speech Loudness....................................... 17
Fig Bl Sound Pressure Spectrum of Continuous Speech at Two Inches from the Lips of
a Talker. ............................................ . ....... 19
8327
IEEE Standard
Method for Determining Objective Loudness 
Ratings of Telephone Connections
1. Introduction
The methods that are used to measure the 
transmission performance of telephone connec 
tions may be divided into two classes: objective 
methods and subjective methods. This standard 
considers an objective method that can be used 
for measuring telephone connections in a man 
ner that reflects the subjective attribute of loud- 
ness with an accuracy suitable for most tele 
phone transmission engineering problems. The 
performance measure is expressed in terms of a 
defined reference and is referred to as an objec 
tive loudness rating.
The objective method utilizes a sound source 
to activate the telephone transmitter, and an 
acoustic coupler and associated microphone 
(artificial ear) as an acoustic termination for 
the telephone receiver. The sound source con 
sists of a source of electric energy, a special 
type of loudspeaker unit (artificial mouth), 
and such supplementary electric and acous 
tic components as may be required so that 
the ensemble provides a controlled sound field.
The artificial mouth and artificial ear provide 
a simpler means of measuring characteristics of 
telephone connections than is possible with the 
human mouth and ear. The practical design of 
artificial mouths and artificial ears is such that 
they only approximate their respective human 
counterparts. Thus telephone connection char 
acteristics measured using these devices will 
only approximate and not duplicate those 
characteristics measured with human mouths 
and ears. However, experience has shown that 
characteristics determined using these devices 
are highly useful in telephone transmission 
engineering.
Subjective methods for rating the transmis 
sion performance of telephone connections 
involve human talkers and listeners. Commonly
used subjective test methods include those 
based on loudness assessment, articulation, 
and judgment. [1-4]. 1 The particular method 
employed in any given .situation depends on 
the transmission parameter(s) to be evaluated 
and on the performance measure criterion of 
interest, for example, articulation or loudness.
Subjective methods have the particular ad 
vantage that ratings obtained are direct meas 
ures of performance. A major disadvantage of 
subjective methods is that they often require 
large groups of human subjects for long time 
periods in order that the results have signifi 
cance. Objective methods, on the other hand, 
involve somewhat simpler and better controlled 
measurements, and a large number of measure 
ments can be made in a relatively short period 
of time. Moreover, measurements can be ob 
tained that reflect subjective evaluation with 
suitable accuracy.
This standard is concerned with a specific ob 
jective method of determining the loudness 
ratings of telephone connections. The method 
is based on objective measurements and com 
putations performed in such a manner that the 
numerical results obtained reflect the subjec 
tive attribute of loudness.
The method was derived, employing certain 
simplifying assumptions, to combine simplicity 
and reasonably close agreement between objec 
tively determined results and subjective re 
sponses. (See Appendix A.) Results obtained 
with the method described in this standard and 
the relation of these results to subjective test 
results may vary with design, for example, size 
and shape of the telephone handset and the 
type of circuitry used to control equalization
1 Numbers in brackets refer to those of the references 
listed in Section 4 of this standard.
8328
Sfcd 661-1979 IEEE STANDARD METHOD FOR DETERMINING OBJECTIVE
or output level, or both. Thus, specific instances 
might occur where the results obtained accord 
ing to the method described will not be suit 
able for transmission engineering purposes, and 
supplementary subjective measurements may 
be required. It would, therefore, appear desir 
able to establish correlation between subjective 
measurements and objective measurements 
separately for each telephone set design before 
the measurements obtained using the method 
of this standard are interpreted to reflect loud- 
ness performance under conditions of actual 
use.
2. Scope and Purpose
2.1 The purpose of this standard is to describe 
a practical and reproducible method of deter 
mining the loudness ratings of telephone con 
nections. Loudness rating may be measured 
directly using appropriate test instruments and 
facilities, as specified in this standard, or may 
be computed using the amplitude-frequency 
characteristic of the connection measured in 
accordance with IEEE Std 269-1971 [5].
2.2 Loudness ratings determined using this 
standard may not exactly duplicate subjective 
loudness evaluations. Moreover, measured rat 
ings and computed ratings determined using this 
standard may not agree, particularly if the con 
nection incorporates nonlinear elements. How 
ever, differences are expected to be acceptably 
small for engineering purposes. For example, 
differences for connections utilizing linear 
microphones are expected to be small, result 
ing only from instrument and measurement 
error, while for connections employing non 
linear microphones, for example, carbon micro 
phones, the differences may be larger.
NOTE: For the purposes of thi» standard, a linear micro 
phone is one that exhibits a one-to-one relation between input pressure and output voltage over its normal oper 
ating range.
2.3 The procedures given in this standard may 
be used for determining the loudness rating of 
partial and complete telephone connections. 
For complete telephone connections, compris 
ing overall and sidetone transmission paths, the 
procedures involve measurement of acoustic 
input and output pressures.
For partial telephone connections comprising 
transmitting, receiving, or connection paths,
the procedures involve measurement of acous 
tic pressures and electric voltages.
2.4 Transmission planning of switched tele 
phone networks is generally accomplished by 
working with parts of connections, for example, 
customer loops (telephone sets, line facilities, 
and feeding bridges) or trunks, to ensure that 
when these parts are switched together, the re 
sulting overall connections perform satisfactori 
ly. When planning is based on loudness, the 
sum of the loudness losses determined for parts 
of a connection should closely approximate the 
loudness loss of the overall connection. For 
such purposes the recommended analysis band 
width is 300-3300 Hz, which approximates the 
bandwidth of the more band-limiting compo 
nents typically found in modern telephone net 
works. There may be cases in which a wider 
bandwidth would be desirable (see Appendix A), 
and the methods of this standard will accom 
modate such wider bandwidths.
2.5 The method of this standard is based on 
specification of (1) characteristics of a suitable 
artificial mouth, (2) a standard artificial ear, 
and (3) appropriate auxiliary measuring instru 
ments and facilities. The method is intended 
for rating connections involving telephone sets 
equipped with handsets. The applicability of 
the method for the measurement of telephone 
sets incorporating special devices such as noise- 
exclusion transmitters, distant-talking transmit 
ters, ear insert receivers, or noise-exclusion re 
ceivers (receivers equipped with circumaural 
earpads) has not been reviewed. However, the 
loudness theory on which this standard is based 
is sufficiently general that advances in the art 
may permit measurement of many such special 
devices using the methods specified in this 
standard.
3. Definitions
NOTE: For terms not listed in this section, see Section 
3 of IEEE Std 269-1971 (5], ANSI Sl.1-1960 (R1976) 
[6], or ANSI/IEEE Std 100-1977 [7].
3.1 Loudness Rating. The amount of frequency- 
independent gain that must be inserted into a 
system under test so that speech sounds from 
the system under test and a reference system 
are equal in loudness.
3.2 Reference System. A system that provides 
0 dB acoustic gain between a mouth reference
8329
LOUDNESS RATINGS OF TELEPHONE CONNECTIONS Std 661-1979
point at 25 mm in front of a talker's lips and 
an ear reference point at the entrance to the 
ear canal of a listener, when the listener is using 
an earphone. This system is assigned a loudness 
rating of 0 dB. The frequency characteristic of 
the system must be flat over the range 300-3300 
Hz and show infinite attenuation outside of 
this range.
NOTES:
(1) If an actual reference system is constructed for 
subjective comparison purposes, the system response at 
300 and 3300 Hz shall be down 3   1 dB relative to the 
mid band response. The gain of the system shall be ad 
justed to compensate for the finite slope of the filter 
skirts and deviation from flatness of the pass band. The 
amount of this adjustment can be determined by first 
calculating the OLR (3.3) over a frequency range that 
includes at least the 50 dB down points of the real 
response, and next calculating the OLR of the ideal 
response, over the same frequency range. The difference 
between the OLRs is the required gain adjustment.
(2) To the extent that the artificial mouth and arti 
ficial ear replicate their average human counterparts, a 
virtual reference system is introduced by reason of the 
calibration of the test system described in Section 5.
3.3 Objective Loudness Rating (OLR). The 
rating of a connection or its components when 
measured according to this standard.
3.4 Voltage and Pressure Levels. Voltage and 
pressure levels (Vr, Vw , SE, and SM) as used 
in definitions of this section are measured (as 
described in Section 5 of this standard) or com 
puted (as described in Section 6 of this stand 
ard).
3.5 Overall Objective Loudness Rating (OOLR)
OOLR = - 20 log.o —
FT = output voltage of the transmitting com 
ponent (in millivolts)
NOTE: Normally occurring TOLRs will be in the -30 
to -55 dB range. These numbers are a result of the units 
chosen and have no physical significance.
3.7 Receiving 
(ROLR)
Objective Loudness Rating
ROLR = - 20 logic (Eq3)
where 
Vw = open-circuit voltage of the electric
source (in millivolts)
SE = sound pressure at the ear reference 
point (in pascals)
NOTE: Normally occurring ROLRs will be in the 40 
to 55 dB range. These numbers are a result of the units 
chosen and have no physical significance.
3.8 Sidetone 
(SOLR)
Objective Loudness Rating
SOLR = -20 log.o
where
(Eq 4)
(Eql)
SM - sound pressure at the mouth reference 
point (in pascals)
SE = sound pressure at the ear reference 
point (in pascals)
3.9 Electrical Objective Loudness Rating 
(EOLR). For a network
where
SE
sound pressure at the mouth reference 
point (in pascals)
sound pressure at the ear reference 
point (in pascals)
3.6 Transmitting Objective Loudness Rating 
(TOLR)
TOLR = - 20 loglo (Eq2)
where
SM = sound pressure at the mouth reference 
point (in pascals)
3 The pascal (Pa) is a unit of pressure that is equal to 1 N/m1 (newton per square meter).
EOLR = - 20 log,0
where
(Eq5)
= open-circuit voltage of the electric 
source (in millivolts)
= output voltage of the network (in 
millivolts)
3.10 Source/Load Impedance. For the purposes 
of this standard, the source/load impedance 
used for determining loudness ratings (see 3.6- 
3.9) is considered to be 900 £1 resistive. See 
also 5.2.11 and 5.3.3.
3.11 Loudness Equation. Loudness voltages (in 
millivolts) and pressures (in pascals) are deter 
mined in accordance with Eq 6.
8330
IEEEStd 661-1979 IEEE STANDARD METHOD FOR DETERMINING OBJECTIVE
or
N 
j'2\
logic
(Eq6)
where
fj - specific frequencies of the N frequencies 
selected for analysis
*; = the signal level (in dBPa or dBmV)3 at 
frequency fj
Loudness voltages and pressures are expressed 
in decibel-like form using Eq 7.
SE. SM , V'w or V± = 201og,0 X
£ Uog,o -   
;-2\ //-!/
log 10
4. References
(Eq7)
[ 1 ] IEEE Std 297-1969, Recommended Prac 
tice for Speech Quality Measurements.
[2] ANSI S3.2-1960 (R1971), American Na 
tional Standard Method for Measurement of 
Monosyllabic Word Intelligibility.
[3] ANSI S3.5-1969 (R1973), American Na 
tional Standard Methods for the Calculation 
of the Articulation Index.
[4] CCITT (International Telegraph and 
Telephone Consultative Committee) Recom 
mendation P 72, Measurement of Reference 
Equivalents and Relative Equivalents, CCITT 
Green Book, vol 5, International Telecom 
munication Union, 1973, 2 Rue de Varembe, 
1211 Geneva 20, Switzerland.
3 dBPa * decibles relative to 1 pascal; dBmV - decibels relative to 1 
millivolt.
[5] IEEE Std 269-1971, Standard Method 
for Measuring Transmission Performance of 
Telephone Sets.
[6] ANSI Sl.1-1960 (R1976), American 
National Standard Acoustical Terminology 
(Including Mechanical Shock and Vibration).
[7] ANSI/IEEE Std 100-1977, Standard 
Dictionary of Electrical and Electronics Terms.
[8] ANSI Sl.12-1967 (R1972), American 
National Standard Specifications for Labora 
tory Standard Microphones.
[9] ANSI SI.10-1966 (R1976), American 
National Standard Method for the Calibration 
of Microphones.
[10] ANSI S3.7-1973, American National 
Standard Method for Coupler Calibration 
of Earphones.
[11] CCITT Recommendation P 51, pt B, 
Artificial Ear Provisionally Recommended by 
the CCnT, CCITT Orange Book vol 5, 
International Telecommunication Union, 1977, 
2 Rue de Varembe, 1211 Geneva 20, Switzer 
land.
[12] SULLIVAN, J. L., A Laboratory System 
for Measuring Loudness Loss of Telephone 
Connections. Bell System Technical Journal. 
vol 50, no 8, Oct 1971, pp 2663-2739.
5. Instrumental Method
5.1 General. The measuring system used in the 
instrumental method consists of a sending end 
and a receiving end (see 5.3). The test equip 
ment required to realize the measuring system 
is described in 5.2.
5.2 Test Equipment. The following test equip 
ment is required for the instrumental determi 
nation of objective loudness ratings of telephone sets: *<
(1) Artificial mouth
(2) Standard circuits
(3) Pressure microphone
(4) Artificial ear coupler
(5) Sweep frequency oscillator
(6) Indicator amplifier
(7) Microphone amplifier
(8) Rating attenuator
(9) Indicator
(10) DC voltage and current meters
(11) Impedance-matching network
5.2.1 Artificial Mouth. See 4.2 of IEEE Std 
269-1971 [5].
8331
LOUDNESS RATINGS OF TELEPHONE CONNECTIONS
IEEE Std 661-1979
5.2.2 Standard Circuits. See 4.3 of IEEE Std 
269-1971 [51.
5J2.3 Microphone. See ANSI Sl.12-1967 [8] 
and SI. 10-1966 [9].
The type of microphone used should be that 
appropriate for the artificial ear coupler 
(see 5.2.4). For calibration of the artificial 
mouth, the microphone should have a flat free- 
field response. This may be accomplished by 
inserting a compensating filter in the micro 
phone amplifier or by using a modified micro 
phone especially designed to have a flat, free- 
field response.
5.2.4 Artificial Ear Coupler. The IEC coupler 
is used as in 4.4 of ANSI S3.7-1973 [10]. See 
alsoRef [11].
5.2.5 Sweep Frequency Oscillator. The oscil 
lator has an output frequency that varies loga 
rithmically with time, sweeping the range from 
300 to 3300 Hz at a rate of between 2 and 10 
sweeps per second. At any point over the 
sweep range, the frequency must be within   3% 
of its nominal value. The sweep waveform may 
be sawtooth or triangular shaped. The output 
level should be constant within  0.25 dB over 
the frequency range. The total distortion should 
be less than 1% at any level and frequency 
encountered.
5.2.6 Indicator Amplifier. An amplifier is re 
quired to increase the level of the input signal 
to a level suitable for the indicator. The fre 
quency response characteristic should be con 
stant within  0.25 dB over the 200-5000 Hz 
range. The total distortion should be less than 
1% over the frequency range and up to the 
maximum levels encountered.
The amplifier should have sufficient signal- 
handling capability to operate 10 dB above the 
maximum level applied to the indicator. See 
5.2.9.
The input and output impedance character 
istics should be chosen so as not to interact 
unfavorably with the preceding stage, the 
following stage, or attenuator calibration.
5.2.7 Microphone Amplifier. See 4.6 of 
IEEE Standard 269-1971 [5].
5.2.8 Rating Attenuator. The attenuator 
should be 600 fl and purely resistive, and have 
steps of 10 dB  0.1 dB when used with a meter 
with a calibrated scale. When used with a meter 
with a single reference point, the recommended 
steps are 10, 1, and 0.1 dB with limits of 
 0.1,  0.01, and  0.01 dB, respectively. A 
minimum range of 60 dB is recommended.
5.2.9 Indicator. The indicator is a device 
that measures and displays the input signal in 
such a manner that the reading is proportional 
to the loudness rating. The indicator consists 
of:
(1) A rectifier
(2) A compressor
(3) A meter
The indicator should have the performance 
characteristics given in 5.2.9.1 through 5.2.9.6.
5.2.9.1 The meter scale should be marked 
in such a manner that for every 1 dB change in 
steady input signal, the meter reading changes 
by 1 dB. Alternatively, a single point may be 
used as a reference on the meter scale, and all 
readings taken from an external attenuator.
It will be found convenient to have the 0 dB 
point or reference point 3-5 dB below full 
scale. Points below 0 dB should be marked 
positive; those above, negative.
5.2.9.2 The indicator response to time- 
varying signals shall follow the law:
 -  (Eq 8)
where, y is the meter reading, x is the input sig 
nal, and k is a constant. This is equivalent to a 
2.2 to 1 dB compression ratio. Thus, a 10 dB 
change in input signal level produces a 4.54 dB 
change in the input to the meter coil, but, as 
specified in 5.2.9.1, appears on the meter scale 
as a 10 dB change.
NOTE: Commercial devices with exponent 0.5 that fall 
within this tolerance range are available.
5.2.9.3 The rectifier should be of the true 
rms type with a crest factor not less than 3:1. 
The time constant should be short relative to 
the sweep time, while the meter time constant 
should be long relative to the sweep time in 
order to average the signal over the sweep. 
See 5.2.9.4.
5.2.9.4 The indicator meter damping shall 
meet the following requirements:
Oscillator Sweeps Meter Rise or Fall Time 
per second (seconds, minimum)
2
6
10
5
2
1
8332
Std 661-1979 TKKF. STANDARD METHOD FOR DETERMINING OBJECTIVE
The rise and fall times are devined as the time 
it takes the meter pointer to move from a 
steady state at 20 dB below full scale, to within 
0.5 dB of full scale and from full scale to within 
0.5 dB of 20 dB below full scale, when a steady- 
state signal that will give this deflection is 
applied.
The rise and fall times are measured by having 
two steady-state signals available, one resulting 
in full-scale deflection, the other 20 dB below 
full scale. The transition time from one state to 
within 0.5 dB of the other state is the fall or 
rise time.
For system calibration (5.4), it may be found 
convenient to use a shorter time constant.
5.2.9.5 The indicator deflection should be 
independent of frequency over the 200-5000 Hz 
range and should have an accuracy of  0.5 dB 
over the calibrated range of the indicator.
5J2.9.6 The attenuator (5.2.8) and ampli 
fier (5.2.6) provide signals of optimum level to 
the compressor and meter.
5.2.10 DC Voltage and Current Meters. See 
4.12 and 4.13 of IEEE Std 269-1971 [5].
5.2.11 Impedance-Matching Network. An 
impedance-matching network with an attenua 
tion of 6 dB is inserted in the receiving end to 
provide impedance match between the 900 SI 
resistive source/load impedance and the 600 SI 
rating attenuator. For this case (see Fig 1), 
R l * 520.1 Sl,Rt * 18.8 SI, and R3 *983.9 SI.
For any other source/load impedance (see 
5.3.3), the network may be designed as shown 
in Fig. 1. For this network:
c-
2V 3.
3.98-1
3'98 +1 
3.98-1
(Eq 9a) 
(Eq 9b) 
(Eq 9c)1 ' 3.98-1 " 3
where
Z] = the system impedance 
Z2 = 600J2
An impedance-matching network may be re 
quired to provide impedance match between 
the microphone amplifier output impedance
-VW-
vw
'•R.
Figl 
H-Pad Circuit
and the 600 SI rating attenuator. The procedure 
outlined in this subsection may be used in the 
design of this network if required.
5.3 Measuring System. The measuring system 
can conveniently be divided into the sending 
end (Fig 2) and the receiving end (Fig 3), with 
the telephone connection under test inserted 
between them. The sending end provides elec 
tric or acoustic signals to the connection under 
test, and the receiving end measures acoustic or 
electric outputs from the connection under 
test.
5.3.1 The Sending End. The sending end 
consists of a sweep frequency oscillator coupled 
either to an artificial mouth to provide an 
acoustic source or to an impedance to pro 
vide an electric source. The output impedance 
of the electric source shall be purely resistive, 
900 Si   1%. The output shall be independent 
of frequency within  0.25 dB over the 200- 
5000 Hz range. (See Appendix B.)
5.3J2 The Receiving End
5.3.2.1 The receiving end consists of an 
acoustic and an electric subsection coupled 
to the indicator.
5.3.2.2 The acoustic subsection consists 
of an artificial ear coupler, a microphone, 
a microphone amplifier, and an impedance- 
matching network.
5.3.2.3 The electric subsection consists 
of an impedance-matching network with an 
insertion loss of 6 dB.
5.3.3 Source/Load Impedance Other Than 
900 n. The definitions (Section 3) and mea 
suring system (5.3.1 and 5.3.2) apply for a 
900 SI resistive source/load impedance. For 
any other impedance the following apply:
8333
LOUDNESS RATINGS OF TELEPHONE CONNECTIONS
For a source/load impendence of Z, Vwz 
should be set equal to VW900 ' V Z/900. The 
rating equations then become:
OOLR = -20 log,0
TOLR = -20 log,0 
ROLR = -201og,0 .
(Eq lOa)
(Eq lOb) 
(Eq lOc)
SOLR » -20 log,0
EOLR = -20 log,0
Std 661-1979 
(Eq lOd)
(Eq lOe)
The output and load impedances of the test 
equipment should be adjusted to the proper 
values and the matching network in the receiv 
ing end should be changed, but the 6 dB loss 
maintained (see 5.2.11). The above procedure 
maintains the same numerical values for 
loudness ratings at different impedances, as can 
be shown by insertion of ideal transformers.
Fig 2 
Sending End of Measuring System
(See 3.10 and 5.2.11.
SWEEP FREQUENCY 
OSCILLATOR
I ACOUSTICAL ARTIFICIAL > SOURCE 
MOUTH )
ELECTRICAL 
SOURCE
Fig 3 
Receiving End of Measuring System
 See 3.10 and 5.2.11.
 For measurement of SE (see 3.5, 3.7, and 3.8), the microphone is inserted into the artificial ear coupler.
MICROPHONE 
i/*^SEL=
l>—»
IMPEDANCE
MATCHING
NETWORK
MICROPHONE
AMPLIFIER INDICATOR 
-IMPEDANCE 600 AMPLIFIER 
>< MATCHING | 
NETWORK I
z* :eoo INDICATOR
8334
Std 661-1979 IEEE STANDARD METHOD FOR DETERMINING OBJECTIVE
ARTIFICIAL"]
rrl !/•>, _ TtL _!.««« L- *«DING _r ——— UJ jQ — SET ~lJ£2Ir" MIDCE T.
L____ ———— ,
ACOUSTICAL
/S ——— fsOURcT| 
[ ELECTRICAL
1 SENDING END OF 
, MEASURING SYSTEM
[~ ARTIFICIAL 1
i ACOUSTICAL - ~/\ L- TEL TT• . ——— i y ™ •*? SCT ^
' !*>"*« M^ ___ J^HANOTET
! ELECTRICAL I 
1 1 
1 SENDING END OF . 
i MEASURING SYSTEM
T ELECTRICAL ~| *Z reED1-B ,
1 (.^CET-1*/ ? M10<!E l
ACOUSTICAL
SENDING END OF 
L MEASURING SYSTEM _,
f" ARTIFICIAL"1 1 MOUTH ,
I ACOUSTICAL -^^ Tet ,-
1 . —————— , jP UJP' SET' —— t 1 | SOURCE^ ^J/ 1 ——— 1
———— o —— ]Lr~ — ~ — — — -
1 ELECTRICAL j
1 SENDING END OF 1 
[_ MEASURING SYSTEM _ i
-—— -1 FEEDING _r,__»l TRUNK]— ,,,|0<je -HJO^r-
, ARTIFICIAL .
TEL ^ / E " .
SET —— W / :
HANDSET Q P ———————
ACOUSTICAL :
| INDICATOR") —— 4
\
A
r -
T^n FEEDING *
O0^! BRIDGE
i
B
i — i r* ^}— sir — pjy
HANDSET X3_l>
! 
1
1 
1 
l_ _c
223— r.sr — ^
ELECTRICAL
RECEIVING END OF 
MEASURING SYSTEM
•LECTRICAL :
%>- — — ) INDICATOR!
ACOUSTICAL
RECEIVING END OF 
MEASURING SYSTEM
RTIFICIAL "" 
EAR \
ACOUSTICAL '————— ^ ,
* —— {INDICATOR | ;
ELECTRICAL '
RECEIVING END Of , 
MEASURING SYSTEM ,
-, ""ARTIFICIAL "!i —IV ""
1 WA. ACOUSTICAL 1"— — — — — — -- -QT_p- ——— ~
1 
'• 1
1 1
"X i"^ —— (INDICATOR) .'
———— o | 
ELECTRICAL ,
RECEIVING END OF : 
MEASURING SYSTEM
D
Fig 4 
Test Circuits
A — Measurement of Overall Objective Loudness Rating (OOLR); B — Measurement of
Transmitting Objective Loudness Rating (TOLR); C — Measurement of Receiving
Objective Loudness Rating (ROLR); D — Measurement of Sidetone Objective
Loudness Rating (SOLR);
8335
LOUDNESS RATINGS OF TELEPHONE CONNECTIONS
IEEE 
Std 661-1979
ELECTRICAL
SOURCE -^
ACOUSTICAL
; SENDING END OF 
MEASURING SYSTEM
? MrrwoBK .., . 7.r,lo_
^ UNDER TEST , "V 1 ———————— 1^ i _______ i x^ ——— (INDICATOR
ACOUSTICAL
RECEIVING END OF 
MEASURING SYSTEM
Fig 4   (Continued) 
E   Measurement of Electrical Objective Loudness Rating (EOLR)
5.4 Calibration
5.4.1 Sending-End Calibration
5.4.1.1 Acoustic Source. Switch the os 
cillator to artificial mouth and start the 
oscillator sweep. Adjust the input to the 
artificial mouth for the desired pressure level, 
measured in accordance with 4.2 of IEEE 
Std 269-1971 [5]. For purposes of the present 
standard, the calibration position is a point on 
the center axis 25   1 mm beyond the reference 
plane (lip ring). The preferred pressure level 
is -6 dBPa (0.5 Pa).
5.4.1.2 Electric Source. Switch the os 
cillator to the electric source and start the 
oscillator sweep. Set the open-circuit voltage to 
the desired value, using a voltmeter in accord 
ance with 4.2.3 of IEEE Std 269-1971 [5]. 
(See note after 5.4.2.2 of the present stand 
ard.)
5.4.2 Receiving-End Calibration
5.4.2.1 Electric Subsection. Switch the 
receiving end for an electric input and set the 
rating attenuator to 40 dB. With the input con 
nected to the electric output of the sending 
end, which has been set to the desired value 
(see note after 5.4.2.2 of the present standard), 
adjust the gain of the indicator amplifier for 0 
reading on the meter.
5.4.2.2 Acoustic Subsection. Switch the 
receiving end for an acoustic input. With the 
rating attenuator set at 40 dB, adjust the micro 
phone amplifier gain so that the indicator meter 
reads 0 (or reference point) for an acoustic 
input to the artificial ear microphone identical 
to that to which the artificial mouth was 
adjusted in 5.4.1.1 (-6 dBPa).
NOTE: Practical transmitting objective loudness ratings are in the vincmity of -50 dB; practical receiving objec 
tive loudness ratings are in the vincinity of + 50 dB. It is
therefore most convenient to calibrate the electric 
sending and receiving ends to that 0 dB on the meter 
(with 40 dB setting of the rating attenuator) is -50 dB 
OLR for transmitting and * 50 dB OLR for receiving. This can be done by adjusting the electric output of 
the sending end to 316 mV open circuit and connect 
ing this output to the electric input of the receiving 
end. The amplifier gain of the indicator is then adjusted 
for 0 dB reading.
The 0 dB point for transmitting is 
316/2TOLR = -20 log,0 -50 dB. (Eq lla)
The 0 dB point for receiving is 
ROLR = -20 log.o = * 50 dB' (Eq
The 0 dB point for sidetone is
SOLR = -20 log,0 ^| = 0 dB. (Eq lie) 0.5
The 0 dB point for overall is
OOLR = -20 log.o ^f = 0 dB. (Eq lid) O.o
5.5 Test Procedure
5.5.1 Electroacoustic Measurements. Insert 
the telephone set and loop to be measured in 
the appropriate circuit in accordance with 
Fig. 4. Place the handset on the artificial mouth 
fixture as outlined in IEEE Std 269-1971 [5] .
NOTE: The position resulting from following steps 1-4 of the "standard test position" procedure (5.2.1 of 
IEEE Std 269-1971 [5 ] ) is with the plane of the trans mitter cap vertical. 
Limited tests indicate that for at least one type of telephone set equipped 
with a carbon transmitter, transmitting responses obtained with the 
plajie of the transmitter cap of a handset in a position 45 to vertical, face 
up, more closely approximate the real voice response than do transmitting responses with 
the plane of the transmitter cap vertical. Therefore,
8336
Std 661-1979 TKFF STANDARD METHOD FOR DETERMINING OBJECTIVE
pending wmflmbflitjr of additional information, the 46° 
face-up orientation is provisionally recommended a* 
preferred. This orientation can be accomplished by 
following step 6 of the procedure and by altering the 
artificial month axis from horizontal as may be 
recjuired.
If a carbon microphone is used, condition as 
outlined in 5.2.2 of IEEE Std 269-1971 [5]. 
Apply the appropriate input and adjust the 
rating attenuator for a convenient meter read 
ing (or to the reference point). The indicator 
reading is the sum of the meter reading and (40 
minus the attenuator reading).
Example 1 :
If the attenuator is set at 30 and the meter 
reads +4, then the reading is +4 +(40-30) 
= 14dB.
Example 2:
If the attenuator is set at 50 and the meter 
reads +4, then the reading is +4 +(40-50) * 6 dB.
TOLR (or ROLR) is obtained by summing 
the indicator reading (see Examples 1 and 2) 
and the calibration factors -50 dB (or.+50 dB) 
of Eqs (lla) and (lib). OOLR (or SOLR) is 
numerically equal to the indicator reading.
5.5.2 Electric Measurements. Insert the 
circuit (loop, etc) to be measured between 
the electric source and the electric input to 
the receiving end in accordance with Fig 4 E. 
The EOLR is the sum of the meter reading and 
(40 minus the attenuator reading).
6. Computational Method
Loudness ratings can be determined from 
amplitude-frequency characteristics, measured 
in accordance with Ref [5], using the computa 
tional method. (See 5.4.1.1 for calibration 
position and preferred pressure level.) This 
method is in accordance with a loudness equa 
tion (see 3.11) and the rating definitions of 
3.5 through 3.9.
The loudness ratings can be calculated using 
the loudness equation programmed on a com 
puter. For a given connection, the amplitude 
responses at the frequencies of interest, ob 
tained, for example, from the amplitude 
frequency characteristic, need to be provided.
Alternatively, the form of Fig 5, based on 
the same principles, may be used. This involves 
plotting the amplitude-frequency characteristic 
on the form, determining the area under the
curve, and finding the average ordinate on the 
dB scale.
For transmitting components, the quantities 
of interest are input pressures from the artificial 
mouth and output voltages from the trans 
mitting component at the frequencies of 
interest.
The transmitting objective loudness rating is 
then, in accordance with 3.6 and 3.11 :
TOLR « -201og,0 ---V'
where
(Eq 12)
VT = loudness voltage (in millivolts) 
SM - loudness pressure (in pascals)
The computation in accordance with the loud- 
ness equation of 3.11 or the form of Fig 5 
provides these quantities in decibel-like terms, 
for example, V'T (indBmV)andS'M (indBPa), 
in turn computed from the output voltage and 
the input pressure frequency characteristics. 
An example is given in Table 1.
For receiving, the quantities of interest are 
the output pressures and input voltages as func 
tions of frequency over the band of interest. 
The input voltage should, in theory, have the 
frequency weighting that a receive component 
expects to see when it is part of an overall con 
nection (see Appendix C). However, sufficient 
accuracy for most engineering applications will 
be obtained using no weighting; that is, the 
input voltage level is independent of frequency.
The receiving objective loudness rating is 
then, in accordance with 3.7 and 3.11:
ROLR = -20 log,o
where
SE loudness pressure (in pascals)
one-half the open-circuit loudness 
voltage from a 900 ft source (in 
millivolts)
The computation provides these quantities in 
decibel-like terms, for example, SE (in dBPa) 
and V'w (in dBmV), in turn computed from 
the output pressure and input voltage frequency
8337
HEIGHT IN INCHES
00
ui oo £01
I* •5-
t-*
a to
•»> 
i
>;o
C >
IV
0) 
>
w ni
5'
I m
0
X
5'
3) 
>
Z 
0
a. 
CD
H 0°
H —r 
•n
0m i 
oro 
oOJ
r> -n P .
' S 0
§ 8 SH rn P - 
n 9 o|g«-
5 5 
i N UI
IN) ' 
OJ •
01 . —————————————————————————————————————————————————————————————————————— ^,
Ol * UI O) 7 1 , a 1 V0
. ... i *^.
- M 
- Ol
- UI 
-0)
Boocnui ^ 01 M o m o o o o o o o
RELATIVE SIGNAL LEVEL IN dB
z o
Std 661 -1979 IEEE STANDARD METHOD FOR DETERMINING OBJECTIVE
Table 1 
Example of Computation of
i-nnmuEFing i injM-nw I^OUDDHB luung
Artificial Mouth
(1)
Frequency(Hi)
300
400
500
600
700
1000
1500
2000
2300
2700
3000
3300
Signal ! * !*
Sound Field (dBPi)
(2)Uneomcttd*
-6
-6.8
-7.2
-7.4
-7.6
-6.3
-7.5
-4.9
-6.5
-7
-7.1
-6.3
-6.7
(3)Comcud*
-6
-6.8
-7.2
-7.4
-7.6
-6.3
-7.5
-4.9
-6.6
-7.4
-7.8
-7.4
-6.8
Tnaanit ComponentOutput Volum (dBmV)
(4)
Unoomctcd
30.5
32
33.5
34
34.5
37
38
3942.7
45.5
4542.5
37.4
(5)
Comctcdt
30.5
32.8
34.7
35.4
36.1
37.3"
39.5
37.9
43.3
46.9
46.8
43.8
38.2
The rating may be computed using the TOLR Eq 12 
with either V'T - 37.4 dBmV, S'M » -6.8 dBPa (cor 
responding to a practical source sound field), or V'T = 
38.2 dBmV, S'M » -6 dBPa (corresponding to the 
ideal case where the source sound field is independent 
of frequency). For the former case.
TOLR [ -<37.4) + -44.2 dB (-6-8)1 dB
while for the latter case
TOLR - [-(38.2) + (-6)) dB 
- -44.2 dB
•Entries in column (2) reflect measurements made with 
a typical type-M pressure microphone. These are 
adjusted in column (3) by the free-field microphone 
correction (see 5.2.3).
tCorrected, from column (4). to reflect a flat sound 
field of -6 dBPa at each frequency.
$ Signal level numbers were computed using loudness 
Eq(7).
characteristics. An example is given in Table 2. 
For this computation, it was assumed that 
V'w = + 48 dBmV independent of frequency.
The particular frequencies used in Tables 1 
and 2 were chosen arbitrarily. Selection of spe-
Table2
Example of Computation of 
Receiving Objective Loudness Rating
Frequency
300
400
500
600
700
1000
1500
2000
2300
2700
3000
3300
Signal level*
Receiving Component 
Output Pressure (dBPa)
-6.5
-2.0
-1.6
-2.3
-3.0
-3.6
-2.0
-4.2
-4.3
-3.0
-4.5
-4.5
-3.1
•Signal level number computed using loudness Eq (7). 
NOTES:
(1) The receiving objective loudness rating is then 
ROLR- {-(-3.1)+ (48-6)] -45.1
(2) For sidetone paths and overall connections, the 
procedure is the same as for transmitting and receiving 
except that the quantities used for the computation are 
input and output pressure frequency characteristics 
over the band of interest. Similarly, the procedure is 
the same for connecting circuits except that the 
quantities used are input and output voltage frequency 
characteristics over the band of interest.
cific frequencies used in computing loudness 
ratings are left to the discretion of the user.
NOTE: Guideline*. The method of implementing loud- 
ness computations, for example, automated measure 
ment and calculation, may indicate that for conven 
ience, the frequencies should be evenly spaced on (1) 
a linear frequency scale or (2) a logarithmic frequency 
scale. For (1) no fewer than 31 frequencies should be 
used. For (2) no fewer than 12 frequencies should be 
used, and more than 20 frequencies would not improve 
accuracy significantly. When manually computing loud- 
ness ratings from frequency characteristics, an inflec 
tion point approach may be more convenient.
8339
LOUDNESS RATINGS OF TELEPHONE CONNECTIONS
IEEE Std 661-1979
Appendixes
(These Appendixes are not part of IEEE Std 661-1979, Method for Determining Objective Loudness Ratings of Tele 
phone Connections.)
Appendix A 
Loudness Rating Method
A particular speech loudness computation 
method, depicted in Fig Al, is based on per 
forming certain operations on the speech pres 
sure spectrum that is delivered by a telephone 
connection to the ear of a listener [12]. These 
operations consist of (1) dividing the received 
speech spectrum into a number of different 
frequency bands, (2) determining the loudness 
due to each band, and (3) summing across all 
bands to obtain the total loudness.
The receiving pressure spectrum consists of 
(1) the reference speech spectrum Is applied 
at the transmitting end of a connection modi 
fied by (2) the amplitude transfer characteristic 
R of the connection.
Not all of the received spectrum contributes 
to loudness; that is, that portion of the spec 
trum lower in level than the threshold of
hearing does not contribute. Account is taken 
of this by defining a quantity termed effective 
spectrum Zj which is the received spectrum 
minus X, which can be regarded as the threshold 
of audibility for continuous spectrum sounds.
The effective spectrum is divided into N 
frequency bands, selected such that each 
contributes equally to the total loudness 
produced by a flat effective spectrum. (For 
purposes of illustration, as in Fig Al, N - 50.) 
The effective level in each band is then con 
verted to loudness units, and the loudness units 
summed for the N (for example, 50) bands. 
The resulting sum Ns represents the total 
loudness of the particular received spectrum.
The quantity Ns is interpreted in terms of the 
level of a selected reference signal having the 
same loudness. The selected reference signal
FigAl 
Computation of Speech Loudness
*dB relative to 1 Pa (pascal); 1 Pa— 1 N/m 2 (newton per square meter). 
NOTE: Ls . R, X, and Zs are functions of frequency.
BANDPASS FILTERS CONVERTER
REFERENCE 
SPEECH 
SPECTRUM 
L, (aBPo)"
COMMUNICATION 
SYSTEM 
FREQUENCY - 
RESPONSE, R 
(«B),»« LOSS
NOTE L«,R.XANOZ, ARE 
FUNCTIONS OP FREQUENCY
• fl B RELATIVE TO 1 PASCAL 
l PASCAL > I NEWTON PER
RECEIVED 
SPEECH
SPECTRUM ~ 
<«BP«)»L,
EFFECTIV 
SPEECH
1— SPECTRU
i, («B> =L-R-x
THRESHOLD OF
AUDIBILITY FOR 
CONTINUOUS SPECTRUM 
SOUNDS, X IdBPol*
E
————
r0 TO
F,
f, TO
F2
F.-ITO
F,
F4, TO 
F50
Z.I TO"t
2 t2 TO
"Z
2,, TO
"I
*,so ro
"50 ———— 1
TOTAL LOUDNESS,
N.
1LOUDNESS
UNITS)
SO 
= tr,
i * 1
SQUARE METER
8340
Std 661-1979 IEEE STANDARD METHOD FOR DETERMINING OBJECTIVE
may be a single frequency tone (1 kHz), white 
noise, etc. A more Bgn'*5***"* and meaningful
summed, and the average taken. This average is 
then multiplied by
reference, and one used in the speech loudness 
computation method, is a received speech 
spectrum of known properties.
The speech loudness computation method 
proved reasonably satisfactory for many types 
of engineering studies. However, review of the 
method suggested that certain changes and 
simplifying assumptions could be made, result 
ing in a simpler method that appeared to be 
suitable for most telephone engineering prob 
lems concerned with loudness. The simpler 
method, essentially equivalent to that depicted 
in Fig Al, is based on determining the level of 
a reference signal whose level is independent of 
frequency across the band of interest and 
whose loudness is the same as mat of a test 
signal, which may be an input or output voltage 
or pressure signal.
NOTE: This concept is inherent in most, if not all, 
loudness rating methods. For example, loudness ratings of test 
systems are frequently determined in terms of the flat loss or 
gain (in dB) which needs to be inserted inta a well-defined reference 
system so that the loud- ness of the speech heard 
over the test and reference systems is the same.
The principle of the simpler method referred 
to above is shown in the loudness equation 
given below and in 3.11 of the standard.
Reference signal level  
20101, Z>:2
2.2 I
(M I
——J
2.2
lot. fN/f,
(EqAl)
where
fj - specific frequencies of the AT frequencies 
selected for analysis
Xj = signal level (in dBPa or dBmV) at fre 
quency fj
1LIn the equation, the operation 
10 20 changes 
the dB level to a pressure or voltage. Then the 
2.2 root of this element and of the element at 
the next lower frequency are determined,
log 10 [=log,0 fj -log,0 (fj-l)].
(This operation can be considered as finding 
the loudness of an element of the received 
signal spectrum by finding the area under a 
curve.) The elements are summed across the 
analysis band and then divided by
Iog 10 fN/fi (=log,0 fN -log 10 /,)
where
fa * the highest frequency 
fi = the lowest frequency
to find the average height of the curve. This 
average height represents the relative loudness, 
in dimensionless units, of the received spec 
trum. Taking the 2.2 power of the average and 
then converting to decibel-like terms by 20 
log I0 operation comprises, in essence, finding 
the pressure magnitude (in dBPa) or voltage 
magnitude (in dBmV) of the reference signal 
that has the same loudness as the signal under 
consideration. (Note that the reference signal 
level is independent of frequency.)
The review of the speech loudness computa 
tion method referred to earlier showed that for 
convenience, the acoustic source signal level 
when determining transmitting, sidetone, and 
overall loudness ratings, should be independent 
of frequency. Thus, the reference signal level of 
the source signal is its nns pressure spectrum 
level. For any other acoustic source signal, the 
reference signal level is according to Eq Al. 
Source signals for determining receiving and 
connecting circuit loudness ratings should have 
the spectrum that is, on the average, impressed 
at the input of these connection components 
when they are part of an overall connection. 
(See Appendix C.)
The instrumental method (Section 4 of the 
standard) is based on the loudness equation. 
The sending and receiving ends of the mea 
suring system together incorporate features 
such that their combined operation replicates 
the operations in the loudness equation.
The analysis bandwidth selected for the 
instrumental method was 300-3300 Hz. The 
reason for limiting the bandwidth was a prac-
8341
LOUDNESS RATINGS OF TELEPHONE CONNECTIONS
tical one. The use of partial connection ratings 
as engineering tools implicitly requires that for 
any given connection, the sum of the partial 
ratings (for example, transmitting plus receiving) 
should approximately equal the overall rating. 
Thus, the bandwidth used to obtain these 
ratings should approximate the bandwidth of 
the most restrictive elements) in order to avoid 
cumulating bandwidth penalties when summing 
partial ratings. The specific limits of 300 Hz
IEEE Std 661-1979
and 3300 Hz were selected largely on the basis 
of bandwidth capabilities of broad-band carrier 
systems with 4 kHz channel spacing. In some 
cases, for example, evaluation of a telephone 
sidetone path, a wider analysis band, for 
example, 100-5000 Hz, may permit better 
estimation of the loudness loss. The method 
described in the standard may be used in such
Appendix B 
Weighted Acoustic Source Signal
Bl. General
The theoretical considerations that led to the 
test method specified in this standard require an 
acoustical output from the artificial mouth that 
is fiat over the frequency range and changing 
in frequency logarithmically with time [12]. 
When measuring carbon microphones, it is 
common practice in the industry to amplitude
modulate the acoustic input signal, for instance, 
by the use of a speech-weighting network. If a 
speech-weighting network is used to shape the 
acoustical input to the system under test, it 
should be followed by an inverse speech net 
work in the receiving end of the measuring 
system, so that the overall input to the indi 
cator will be flat when the system is calibrated. 
A curve shape commonly used for speech 
weighting is shown in Fig Bl.
FigBl
Sound Pressure Spectrum of Continuous Speech at 
Two Inches from the Lips of a Talker
NOTE: Averaged and smoothed from data for 13 males and 12 females.
-24
0.to
•a
z
IT
ac3 
en en
UJ<r
a a
I -64
-54
- 74
100 1000 
FREQUENCY IN Mi
lOOOO
8342
Std 661 1979 IEEE STANDARD METHOD FOR DETERMINING OBJECTIVE
B2. System Calibration When Speech 
Weighting is Used
The calculated loudneu rating of the speech 
spectrum shown in Fig Bl over the range of 
300-3300 Hz is -0.6 dB relative to the 
1000 Hz level of the signal. The calculated 
loudness rating of the free-field response of the 
type-M microphone relative to the pressure 
response is -0.1 dB. The free-field correction 
at 1000 Hz is 0 dB. To calibrate proceed as 
follows:
(1) Calibrate the acoustic input subsection 
normally
(2) Place the type-M microphone from the 
artificial ear at the calibration point of the 
artificial mouth. Set the oscillator frequency to 
1000 Hz and with speech weighting in, adjust 
the oscillator output for a reading of 0.6 dB 
on the indicator (+0.6 -0 dB for 1000 Hz free- 
field correction)
(3) Start sweep and switch in the inverse 
speech network. Adjust the indicator amplifier 
gain for a reading of -0.1 dB.
' Appendix C 
Weighted Electrical Source Signal
Reference [12] assumes that the electric 
input during receive tests is shaped to simulate 
the transmitting response of a telephone set. 
Experiments have shown that the effect of mis 
shaping relative to a flat input is less than 
0.5 dB in the case of a typical telephone set of 
modem design.
As the use of a shaped input can lead to 
extensive tests where several types of telephone 
sets are to be evaluated, each with a different 
transmit response, and in view of the slight 
difference in the results, it is recommended 
that a flat input be used for receive tests.
8343
BrODUL 
EMMEOM6 OOOMENR Mk Tht MMMHM Of IEEE IEEE Std 2OM992
IEEE Standard Methods for 
Measuring Transmission 
Performance of Analog and 
Digital Telephone Sets
Circuits and Devices
IEEE Communications Society
Sponsored by the
Transmission Systems Committee
J**my21.1993
Electromagnetics and 
Radiation
FInerg\ and Power
Industrial Applications
Signals and 
Applications
Standards
Coordinating
Committees
, 3KBmt470i Stnx, Mttf Itefc MY WH USA.
SH1S404
8344
Std 269-1992
(Revision of IEEE Std 269-1983)
IEEE Standard Methods for Measuring
Transmission Performance of Analog and
Digital Telephone Sets
Sponsor
Transmission Systems Committee
of the 
IEEE Communications Society
Approved June 18,1992 
EEE Standards Board
Abstract: Practical methods for measuring the transmission characteristics of both digital 
and conventional two-wire analog telephone sets by means of objective measurements on a 
test connection are described. The test results thus obtained may be used as a means of evalu 
ating or specifying the transmission performance of a telephone set on a standardized basis. 
The methods are applicable to telephone sets incorporating carbon or linear transmitters. 
Measurements are over the frequency range most useful for speech: 100-5000 Hz. The test 
methods are not intended to be applicable to special devices, such as noise-exclusion transmit 
ters, distant-talking transmitters, insert-type receivers, or noise-exclusion receivers equipped 
with large ear pads.
Keywords: analog telephone sets, digital telephone sets, telephony, voice transmission 
performance
The Institute of Electrical and Electronics Engineers, Inc. 
345 East 47th Street, New York, NY 10017-2394, USA
Copyright <D 1993 by the Institute 
of Electrical and Electronics Engineers, Inc.
All rights reserved. Published 1993 Printed in 
the United States of America
ISBN 1-55937-234-6
No port of this publication may be reproduced in any form,
in an electronic retrieval syttem or other wise, 
without the prior written permission of the publisher.
8345
neieie standards documents are developed within the Technical Com 
mittees of the IEEE Societies and the Standards Coordinating Commit 
tees of the IEEE Standards Board. Members of the committees serve 
voluntarily and without compensation. They are not necessarily members 
of the Institute. The standards developed within TREE represent a con 
sensus of the broad expertise on the subject within the Institute as well as 
those activities outside of IEEE that have expressed an interest in partic 
ipating in the development of the standard.
Use of an IFEE Standard is wholly voluntary. The existence of an IEEE 
Standard does not imply that there are no other ways to produce, test, 
measure, purchase, market, or provide other goods and services related to 
the scope of the IEEE Standard. Furthermore, the viewpoint expressed at 
the time a standard is approved and issued is subject to change brought 
about through developments in the state of the art and comments 
received from users of the standard. Every IEEE Standard is subjected to 
review at least every five years for revision or reaffinnation. When a docu 
ment is more than five years old and has not been reaffirmed, it is reason 
able to conclude that its contents, although still of some value, do not 
wholly refiect.the present state of the art Users are cautioned to check to 
determine that they have the latest edition of any IEEE Standard.
Comments for revision of KEEP Standards are welcome from any inter 
ested party, regardless of membership affiliation with IEEE. Suggestions 
for changes in documents should be in the form of a proposed change of 
text, together with appropriate supporting comments.
Interpretations: Occasionally questions may arise regarding the mean 
ing of portions of standards as they relate to specific applications. When 
the need for interpretations is brought to the attention of IEEE, the Insti 
tute win initiate action to prepare appropriate responses. Since IEEE 
Standards represent a consensus of ail concerned interests, it is impor 
tant to ensure that any interpretation has also received the concurrence 
of a balance of interests. For this reason 1EKK and the members of its 
technical committees are not able to provide an instant response to inter 
pretation requests except in those cases where the matter has previously 
received formal consideration.
Comments on standards and requests for interpretations should be 
addressed to:
Secretary, IEEE Standards Board 
445 Hoes Lane 
P.O. Box 1331
Piscataway, NJ 08855-1331 
USA
IEEE Standards documents are adopted by the Institute of Electrical 
and Electronics Engineers without regard to whether their adoption may 
involve patents on articles, materials, or processes. Such adoption does 
not assume any liability to any patent owner, nor does it assume any 
obligation whatever to parties adopting the standards documents.
8346
Std 269-1992 TTflfle STANDARD METHODS FOR MEASURING TRANSMISSION
For a sinusoidal signal, an open-circuit voltage of 0.316 V (-10 dB relative to IV) from a 
900 fi source is recommended so as to be consistent with IEEE Std 661-1979 [11]. A value of 
0.251 V (-12 dB relative to 1V) may be used so as to preserve continuity with other measure 
ment standards.The recommendation for a continuous spectrum 
signal is a level of -18 dBV open circuit 
across the frequency band 100 Hz to 5000 Hz.The electric source 
and the measurement circuit should have the capability of operating lin 
early up to a level of approximately 1V.
Me recommended above may be required for specific measurements, e.g.. volume controlNOTE: Lower levels thai
and AGC. The level used should be stated.
6.4.2 Frequency Response. The receive frequency response of the telephone set is the 
RMS-PS of the telephone set acoustic output signal measured in the artificial ear divided by 
the RMS-PS of the input signal.
_ . _ _ RMS-PS of Acoustic Output Receive Frequency Response = of Electrical Input ._ (Eq 7)
The input signal is the electrical signal developed by the generator across a 900 A load 
without the telephone connected. In practice, the input signal is obtained by measuring the 
RMS-PS at the generator reference point and applying a correction response. The generator 
reference point is an electrical terminal in the generator circuit that is unaffected by loading 
due to the electrical impedance of the telephone. The measured results should be reported as 
decibels relative to one pascal per volt (dBPa/V) with respect to the voltage across the 900 Q 
calibration load (cal load) in Fig 7.
GENERATOR 
REFERENCE 
POINT
KV, 900 A
High Input Impedance 
Low Output Impedance 
Amplifier
890 a
GENERATOR 
REFERENCE 
POINT
Note: Assumes high 
10 & Impedance generator
Telephone Set, 
Feeding Bridge 
and Loop
Telephone Set, 
Feeding Bridge 
and Loop
Fig? 
Receive Source Configurations
6.4.2.1 Sinusoidal Method. For the sinusoidal method, the input signal is typically held 
constant and the receive frequency response is denned by Eq 8.
Receive Frequency Response = Acoustic Output in Artificial EarConstant Electrical Input at 900 Si Calibration Load (Eq8)
8347
IEEE 
PERFORMANCE OF ANALOG AND DIGITAL TELEPHONE SETS Std 269-1992
6.4.2.2 Continuous Spectrum Method. For the continuous spectrum method, the 
receive frequency response is defined by Eq 9.
rRMS-PS of Acoustic Output in Artificial Ear"! Measured Response 
_ I RMS-PS at General Reference Point J Recewe Frequency Response =   r RMS-PS at 900 Q Calibration LoaQ  
LRMS-PS at General Reference Point J CorTecO<>n Response
(Eq9)
The correction response, measured without the telephone connected, is the RMS-PS devel 
oped by the generator across a 900 Q load divided by the RMS-PS at the generator reference 
point. (See Fig 7.)
Tb determine the receive frequency response, measure the correction response and then 
measure the receive sound pressure level spectrum and the spectrum at the generator refer 
ence point. Apply the results to Eq 9.
In all continuous spectrum measurements, averaging time shall be sufficient to obtain the 
required accuracy in the spectrum estimates.
When using the preferred signal of 5.5.1, averaging time shall be at least one full period of 
the signal. Averaging time shall be stated.
6.4.3 Noise. Connect the telephone set to the feed circuit of Fig la or Fig Ic and, if desired, 
a loop circuit. The handset should be isolated from sound input and mechanical disturbance 
that would cause significant error. Measure the signal from the artificial ear using the meter 
specified in 5.15.2. Measurements may be made over a range of loop currents.
6.4.4 Input-Output Linearity. This measurement is comprised of steps in 6.4.2 but is 
made for input levels representing the total range that the telephone set is expected to 
encounter in use. The measurement may be made at any frequency or over any frequency 
band of interest. It should be noted that when the preferred signal of 5.5.1 is used, the peak- 
to-nns ratio is about 10 dB higher than the ratio for sinusoidal signals. For a linear character 
istic, the output should follow an input level change decibel for decibel. Acoustic limiting of 
high-level steady-state signals is obtained when an increase in input levels results in no 
increase in the acoustic output.
6.4.5 Distortion. The discussion of 6.3.5 applies. Receiving distortion may be measured 
using the test circuits of Figs 5b or 6b and the procedures of 6.4.1 to generate the input signal.
6.4.6 Equalization. Receiving equalization should be measured using one of the circuits of 
Fig 5b or Fig 6b. For various line currents representing the range of currents the telephone is 
expected to encounter in use, the receive characteristics should be measured as in 6.4.2.
6.4.7 Peak Acoustic Pressure (Surge Input). Peak acoustic pressure can be measured 
by following this procedure:
(1) Connect the line terminals of the telephone set to a battery feed circuit of Fig 1.
(2) Connect the surge generator of Fig 8 to the battery feed (telephone side) so that termi 
nal A is connected to the positive terminal of the battery feed.
(3) With the ear-cap of the telephone set sealed to the artificial ear, measure the peak 
pressure in the artificial ear while operating the surge generator. An oscilloscope or a 
sound level meter, having an unweighted "peak hold" mode setting, with a time con 
stant equal or less than 50 us, is used to make the measurement.
(4) Reverse the telephone set connection and repeat step 3.
8348
IEEE
Std 269-1992 IEEE STANDARD METHODS FOB MEASURING TRANSMISSION
7. Test Procedures for Digital Sets
7.1 General. Use of a reference codec test methodology means that test procedures for digital 
telephone sets, in general, follow those for analog telephone sets. An important difference, 
however, concerns the test circuits. See 6.1 for general information on procedures.
7.2 Standard Circuits. The standard circuits for transmission measurements are shown in 
Figs 11 through 14. Fig 11 shows the general test arrangement for digital telephone sets with 
a digital telephone set interface and the test bed containing the reference codec. Figs 12 and 
13 show measurement setups for the sinusoidal method and the continuous spectrum method.
7.3 Transmit Frequency Response. The test circuit for transmit is shown in Fig 12a or Fig 
13a. The measurement procedure should be as in 6.3.2.
'M
Digital Set
P-
1
Sidetone 
Pathl
A/
\D 
A \
Control
1
Interface
"Reference Codec"
D / 
/A
\A
900 SI
900 Si
Fig 11 
Digital Telephone Test Arrangement
7.4 Receive Frequency Response.. The test circuit for receive is shown in Fig 12b or Fig 
13b. The measurement procedure should be as in 6.4.2.
7.5 Sidetone Frequency Response. The test circuit for sidetone is shown in Fig 12c or Fig 
13c. The measurement procedure should be as in 6.5.2. The reference codec is not used in the 
measurement but may remain in the test circuit.
7.6 Overall Frequency Response. The overall response should be measured using two tele 
phone sets back-to-back, connected through the interfaces without the ideal codec. The test 
circuit for overall is shown in Fig 12d or Fig 13d. The measurement procedure should be as in 
6.6.2.
7.7 Signal-to-Distortion Ratio. The handset should be isolated from sound input or 
mechanical disturbance that may introduce significant error.
7.7.1 Transmit. The transmit signal-to-distortion ratio is the ratio of the signal power of a 
pure tone to the C-message weighted distortion power at the output of the reference codec. 
Using Fig 12a, transmit a pure tone following the procedures in 6.3.2. The output signal is 
measured according to Section 4.3.2 of IEEE Std 743-1984 [12]. The pure tone typically has a 
frequency between 1004 Hz and 1020 Hz and an input level between 60 dBSPL and 
105 dBSPL.
8349
PERFORMANCE OF ANALOG AND DIGITAL TELEPHONE SETS
IEEE 
Std 269-1992
CM«A«.
Gener
Art.
rave
ator
1*
Uai
Kxrth J3 *-
\a m i
or*"«>
b *b
1
Digital 
Telephone
i
Generator
Program
Interface :
i —— .
Microphone
AmpHfier
i
900 £ _^wv-
Reference 
Codec
900 &
Measuring 
Device
Microphone 
AmpHfier
Figure 12a Transmit
—=fl>
Art. Ear Digital Ttwpnont
900 fl.
Reference Codec
Measuring 
Device
Figure 12b Receive
Interface •^•^•B °/ / A
9002.
Reference 
Codec
900 £
Figure I2c Sidetone
Figure 12d Overall
Fig 12 
Digital Test Circuits—Sinusoidal Method
8350
Std 269-1992 IEEE STANDARD METHODS FOR MEASURING TRANSMISSION
Continuous 
Spectrum 
Generator
Art. Mouth 1r~Ti 1— q j
Microphone
*I
1 Diojtal Telephone
to a or b
= Interface
Plotter
D/J££
^_ " Reference
COO>C
i" 'i Computer »
900 £
ch.1 c
Spectrum 
Analyzer
b2
Figure 13a Transmit
Figure I3b Receive
to
^••H
r 
"7
••• 
1C
•••i
Microphofrf
AMMklM«*B»Aflnplfncr
ATT^
Art, i — N 
touthl — V
Continuous 
Spectrum 
Generator
J
Spectrum 
Analyzer
Digital
Tele)
>
none
f
Microphone 
Amplifier
r b/ *
» Computer *£ Plotter
3-7 900fl
/ A Reference
900A -vs<«v
Figure 13c Sidetone Art. Ear
Continuous
Spectrum
Generator
Figure 13d Overall
Fig 13 
Digital Test Circuits-Continuous Spectrum Method
8351