Motorola MOTOKRZR K1 Motomanual page 99

Hearing Aid Compatibility with Mobile Phones
Some Motorola phones are measured for compatibility with Hearing Aids
hearing aids. If the box for your particular model has "Rated for
Hearing Aids" printed on it, the following explanation applies.
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
All manuals and user guides at all-guides.com
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