The wireless telephone industry has developed
a rating system for wireless phones, to assist
hearing device users find phones that may be
compatible with their hearing devices. Not all
phones have been rated. Phones that are rated
have the rating on their box or a label located on
the box.
The ratings are not guarantees. Results will vary
depending on the user’s hearing device and
hearing loss. If your hearing device happens to be
vulnerable to interference, you may not be able
to use a rated phone successfully. Trying out the
phone with your hearing device is the best way
to evaluate it for your personal needs.
M-Ratings: Phones rated M3 or M4 meet FCC
requirements and are likely to generate less
interference to hearing devices than phones that
are not labeled. M4 is the better/higher of the
two ratings.
Hearing devices may also be rated. Your
hearing device manufacturer or hearing health
professional may help you find this rating. Higher
ratings mean that the hearing device is relatively
immune to interference noise. The hearing aid
and wireless phone rating values are then added
together. A sum of 5 is considered
acceptable for normal use. A sum
of 6 is considered for best use.
In the above example, if a hearing aid meets the
M2 level rating and the wireless phone meets the
M3 level rating, the sum of the two values equal
M5. This should provide the hearing aid user
with “normal usage” while using their hearing
aid with the particular wireless phone. “Normal
usage” in this context is defined as a signal
quality that is acceptable for normal operation.
The M mark is intended to be synonymous with
the U mark.
The T mark is intended to be synonymous
with the UT mark. The M and T marks
are recommended by the Alliance for
Telecommunications Industries Solutions (ATIS).
The U and UT marks are referenced in Section
20.19 of the FCC Rules. The HAC rating and
measurement procedure are described in the
American National Standards Institute (ANSI)
C63.19 standard.
For information about hearing aids and digital
wireless phone
•
Fcc Hearing Aid Compatibility and Volume
Control http://www.fcc.gov/cgb/dro/hearing.
html
•
Gallaudet University, RERC
http://tap.gallaudet.edu/DigWireless.KS/
DigWireless.htm
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