Operation Manual

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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 this.
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 example illustrated above, 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’s 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