167
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.
T-Ratings
: Phones rated T3 or T4 meet FCC requirements and are
likely to generate less interference to hearing devices than
phones that are not labeled. T4 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 is synonymous for T ratings. 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.
M3 + M2 = 5
T3 + T2 = 5
A837.book Page 167 Wednesday, July 23, 2008 3:28 PM
