16
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’s acceptable
for normal operation.
The M mark is intended to be synonymous
with the U mark. The T mark is intended to be
synonymous with the UT mark.
The M and T marks are recommended by the
Alliance for Telecommunications Industries
Solutions (ATIS). The U and UT marks are
referenced in Section 20.19 of the FCC Rules.
The HAC rating and measurement procedure
are described in the American National
Standards Institute (ANSI) C63.19 standard.
To ensure that the Hearing Aid Compatibility
rating for your phone is maintained, secondary
transmitters such as Bluetooth and WLAN
components must be disabled during a call.
For your safety
