Efficient Networks CENTRA S - Manual (Page 30)

28 Siemens Hearing Instruments
Cell Phone Compatibility
Some hearing instrument users have reported a
buzzing sound in their hearing instruments when
they are using cell phones, indicating that the
cell phone and hearing instruments may not be
compatible. According to the ANSI C63.19
standard (ANSI C63.19-2006 American National
Standard Methods of Measurement of
Compatibility Between Wireless Communications
Devices and Hearing Aids), the compatibility of a
particular hearing instrument and cell phone can
be predicted by adding the rating for the hearing
instrument immunity to the rating for the cell
phone emissions. For example, the sum of a
hearing instrument rating of 2 (M2/T2) and a
telephone rating of 3 (M3/T3) would result in a
combined rating of 5. Any combined rating that
equals at least 5 would provide “normal use”; a
combined rating of 6 or greater would indicate
“excellent performance.”