User's Manual

Cell Phone and Hearing Instrument

Compatibility

Some hearing instrument users have reported a

buzzing sound in their instruments when they are

using cell phones, indicating that the cell phone

and hearing instrument may not be compatible.

The compatibility of a particular hearing aid and

cell phone can be predicted by adding the rating

for the hearing aid immunity to the rating for the

cell phone emissions (ANSI C63.19-2006 American

National Standard Methods of Measurement of

Compatibility between Wireless Communication

Devices and Hearing Aids).

For example, the sum of a hearing aid with a

rating of 2 (M2/T2) and a telephone with a rating

of 3 (M3/T3) would result in a combined rating

of 5. According to the standard, any combined

rating that equals at least 5 would provide “normal

use”; a combined rating of 6 or greater would

indicate “excellent performance.”