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.
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 Alliance for Telecommunications Industries
In the example to the left, 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
Safety
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