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TTY or TDD

Version 1: An abbreviation for teletypewriter. Machinery
or equipment that enables interactive text based communications through
the transmission of frequency-shift-keying audio tones across the PSTN
according to TIA-825-A (A Frequency Shift Keyed Modem For Use On The
Public Switched Telephone Network). As used in this part, the term TTY
includes devices for text-to-text communications along with voice and
text intermixed communications such as voice carry over and hearing
carry over. TTYs may include computers with special modems. TTYs are
a subset of devices called text telephones.

or

Version 2: The term TDD means a Telecommunications
Device for the Deaf, which is a machine that employs graphic communication
in the transmission of coded signals through a wire or radio communication
system.

Status: In Progress

Source of Version 2: ADA,
Title IV, Section 225(a)(2) 

Text from: Telecommunications

 

2.2 If the Product has Speech Output or Throughput
2.2-A - Magnetic Coupling

Products that deliver output with an audio transducer that is normally held up
to the ear must provide a means for effective magnetic wireless coupling
to hearing technologies that allows a user to effectively utilize the
product. This does not apply to headphone, headset, OR
other accessories that plug into a jack on the product.

 Status: Done

 Text from Hardware and Telecommunications

 Source: {508}1194.23(h), {255}11943.43(i)

 

2.2-D - Volume

All products with auditory output beyond simple tonal feedback
or signaling must allow users to adjust the audio level. At
peak volume output they must have less than 12 dB symmetrical clipping
or a total harmonic distortion (THD) less than XXX dB

 For products located in a public place, the maximum
volume level must be at least 80 dB SPL RMS, measured at xx centimeters
from the device at maximum volume setting [possible without XXX distortion].

 For products that will not be used in public places
or where the volume of the public place is controlled to be under 50
dBA SPL RMS, the maximum volume level must be at least 65 dB SPL RMS.

Discussion or rationale: Final level for THD still to be determined.
Question about where are volumes set? Is that where you measure from?
Does this overlap with 2.3.E?

 Status: In Progress

 Text from Self-Contained/Closed

 Source: {508}1194.25(f), {255}1193.43(e)

 Impact:

 External Reference:

 Testability: Formal test method

 Metadata

o Disabilities:
Hard of hearing

o User Activities:
All

o Product
Characteristics: Sound output - speech, Sound output (other than speech)

o Product
Types: All

 

2.2-B - Interference with Hearing Device

Version 1: Interference
to hearing technologies (including hearing aids, cochlear implants,
and assistive listening devices) must be reduced to the lowest possible
level
that allows a user of hearing technologies to utilize the telecommunications
product.

to a level that is most effective in allowing
a user of hearing technologiesToday this includes M3 or M4 and T3 or
T4 in cellular and PCS products

to the level that allows the user of hearing
technologiles that meet the M3 or equivalent to utilize the t/communication
product.

Recommendation: Advisory Note for U.S. use to include information
re existing standards:  TIA Standard for Cordless Phones and the
ANSI standard for cellular and PCS frequency bands and for hearing aid
immunity.  Standards do not exist for other frequency bands and
for any VoIP at this time.

Discussion or Rationale: Problem with Versions 1-3 is that there is
no criterion for how immune a phone should be in measurable terms. There
are hearing aids that are so poor that one could never have a transmitting
device near them. So that cant be met. One idea was to meet a standard
(See version 4) but that would make this specific to particular transmitting
technologies since they are all tied to frequency bands and the transmission
pulse rate.

 Status:
In Progress

 Text
from Hardware and Telecommunications

 Source:
{508}1194.23(i), {255}1193.43(h)

 Impact:

 External
Reference: