Thread Subject: Re: TTY 255 Guidelines and 508 Standards ... for11.27Telecomm Subcomm. Discussion
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From: Diane Golden
Date: Mon, Nov 27 2006 10:15 AM
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An issue we've struggled with is interpretation of 508 Standard 1194.23(c)
which reads "Voice mail, auto-attendant, and interactive voice response
telecommunications systems shall be usable by TTY users with their TTY's."
The definition of TTY in 1194.4 says a TTY is "equipment that employs
interactive TEXT-BASED communications" (my emphasis.) If the definition of
TTY means just text to text communication, then this 508 standard does not
address accessibility for individuals who use text/voice mixed
communications (voice carry-over or hearing carry-over.) I'm not sure how
procurement folks have been interpreting the requirement and/or what they
have been looking for in system response features, just text-text access or
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Sent: Monday, November 27, 2006 10:16 AM
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Subject: [teitac-telecom] TTY 255 Guidelines and 508 Standards ... for
11.27Telecomm Subcomm. Discussion
TO: TEITAC Telecomm Subcommittee Members
>From : Mary Brooner
RE: 11.27.06 Conference call meeting - Topic is TTY
Below are the text segments relating to TTY for discussion today.
Section 255 Guidelines:
22.214.171.124 (C-6). Text Telephone Connectability.
Guideline: Where readily achievable, products which provide a
function allowing voice communication and which do not themselves provide a
TTY functionality shall provide a standard non-acoustic connection point for
TTYs. It shall also be possible for the user to easily turn any acoustic
pickup on the product on and off to allow the user who can talk to intermix
speech (live microphone) with text telephone use.
Rationale: Individuals who use text telephones (TTYs) to communicate
using text-over-telephones must have some non-acoustic way to connect TTYs
to telephones to get clear TTY connections. Acoustic coupling is subject to
interference from ambient noise, as many handsets do not provide an adequate
seal with TTYs. Therefore, alternate (non-acoustic) connections are needed.
Control of the microphone is needed for situations such as pay-phone usage,
where ambient noise picked up by the mouthpiece often garbles the signal
(user needs to be able to mute the handset microphone). Some users of TTYs
cannot hear and use the TTY to receive communication but can talk and use
speech for outgoing communication. The microphone on/off switch on the
telephone should therefore be easy to flip back and forth or have a
push-to-talk mode available.
126.96.36.199 (C-7). Text Telephone Signal Compatibility.
Guideline: Where readily achievable, products providing voice
communication functionality shall be able to support use of all
cross-manufacturer non-proprietary standard signals used by
telecommunication devices designed for use by or with people who are deaf,
hard of hearing or have speech impairments.
Rationale: Some telecommunication systems, which have been developed
and released, compress the audio signal in such a manner that standard
signals used by TTYs are distorted or attenuated, preventing successful TTY
communication over the systems.
Section 508 Standards re TTY
188.8.131.52 Telecommunications E&IT and customer premises E&IT shall be
compatible with peripheral devices and specialized customer premises E&IT
commonly used by individuals with disabilities to achieve accessibility, and
shall comply with the following provisions, as applicable:
184.108.40.206.1 TTY connectability:
E&ITs which provide a function allowing voice communication and which do not
themselves provide a TTY functionality shall provide a standard non-acoustic
connection point for TTYs. It shall also be possible for the user to easily
turn any microphone on and off to allow the user to intermix speech with TTY
220.127.116.11.2 TTY signal compatibility:
E&ITs which include voice communication functionality, shall support use of
all cross-manufacturer non-proprietary standard signals used by TTYs.
18.104.22.168 TTY users shall be able to utilize voice mail, auto-attendant, and
interactive voice response systems directly with their TTY.
22.214.171.124 Voice mail, auto-attendant, and interactive voice response systems
shall provide at least one mode which does not require users to respond
within a timed interval or allows users to adjust the timing and repetition
of those intervals so that the systems can be used both by people with
slower response times and by Telecommunication Relay Services or other
situations where a person is interpreting for or assisting a user.
126.96.36.199 If messaging is supported for voice calls, it shall be supported for
188.8.131.52 Special services such as ANI (Automatic Number Identification) and
ALI (Automatic Location Identification), if provided for voice telephony
users, shall also be provided for users of a TTY and for users who cannot
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