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For your safety
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 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 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 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. To ensure that the Hearing Aid
Compatibility rating for your phone is maintained, secondary transmitters such as
Bluetooth and WLAN components must be disabled during a call.
When you’re talking on a cell phone, it’s recommended that you turn the BT
(Bluetooth) or WLAN mode off for HAC.
