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For Your Safety
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 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 enter 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.
