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The wireless telephone industry has developed a rating system for wireless mobile
devices to assist hearing device users find mobile devices that may be compatible
with their hearing devices. Not all mobile devices have been rated. Mobile devices
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 mobile device successfully. Trying
out the mobile device with your hearing device is the best way to evaluate it for your
: Wireless mobile devices rated M3 or M4 meet FCC requirements and are
likely to generate less interference to hearing devices than mobile devices that are
not labeled. M4 is the better/higher of the two ratings. M-ratings refer to enabling
acoustic coupling with hearing aids that do not operate in telecoil mode.
: Mobile devices rated T3 or T4 meet FCC requirements and are likely to
generate less interference to hearing devices than mobile devices that are not
labeled. T4 is the better/higher of the two ratings. T-ratings refer to enabling
inductive coupling with hearing aids operating in telecoil mode.
Hearing devices may also be rated. Your hearing aid manufacturer or hearing health
professional may help you find this rating. Higher ratings mean that the hearing
device is relatively immune to interference noise.
Under the current industry standard, American National Standards Institute (ANSI)
C63.19, the hearing aid and wireless mobile device rating values are added
together to indicate how usable they are together. For example, if a hearing aid
meets the M2 level rating and the wireless mobile device meets the M3 level rating,
the sum of the two values equals M5.
Under the standard, this should provide the hearing aid user with normal use while
using the hearing aid with the particular wireless mobile device. A sum of 6 or more
would indicate excellent performance.