* In the United States and Canada, the SAR limit for 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.
Hearing Aid Compatibility with Mobile Phones
When some mobile 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
ratings for some of their mobile phones, to assist hearing
device users in finding 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 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 be more usable with a hearing device's
telecoil ("T Switch" or "Telephone Switch") than
unrated phones. T4 is the better/higher of the two
ratings. (Note that not all hearing devices have
telecoils in them.)
Hearing devices may also be measured for immunity to this
type of interference. Your hearing device manufacturer or
hearing health professional may help you find results for your
hearing device. The more immune your hearing aid is, the less
likely you are to experience interference noise from mobile
phones.
Safety Guidelines
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