User's Manual

Your hearing device manufacturer or hearing
health professional may help you find this
rating. Higher ratings mean that the aring
device is relatively immune to interference
noise. The hearing aid and wireless phone
rating values are then added together.A
sum of 5 is considered acceptable for nor-
mal 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 pro-
vide the hearing aid user with “normal us-
age” while using their hearing aid with the
particular wireless phone. “Normal usage”
in this context is defined as a signal quality
that is 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 de-
scribed in the American National Standards
Institute (ANSI) C63.19 standard.
Additional safety information
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