mobile phones used by the public is 1.6 watts/kg
(W/kg) averaged over one gram of tissue. The
standard incorporates a substantial margin of safety
to give additional protection for the public and to
account for any variations in measurements.
FCC Hearing-Aid Compatibility
(HAC) Regulations for Wireless
Devices
On July 10, 2003, the U.S. Federal Communications
Commission (FCC) Report and Order in WT Docket
01-309 modified the exception of wireless phones
under the Hearing Aid Compatibility Act of 1988
(HAC Act) to require digital wireless phones be
compatible with hearing-aids. The intent of the HAC
Act is to ensure reasonable access to
telecommunications services for persons with hearing
disabilities.
While some wireless phones are used near some
hearing devices (hearing aids and cochlear implants),
users may detect a buzzing, humming, or whining
noise. Some hearing devices are more immune than
others to this interference noise, and phones also vary
in the amount of interference they generate.
The wireless telephone industry has developed a
rating system for wireless phones, to assist hearing
device users find phones that may be compatible with
their hearing devices. Not all phones have been rated.
Phones 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
phone successfully. Trying out the phone with your
hearing device is the best way to evaluate it for your
personal needs.
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 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 is
synonymous for T ratings. 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 is 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
