User's Manual

206
Safety
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.
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 is acceptable for normal operation.