User's Manual

phones that are not
labeled. M4 is the
better/higher of
the two ratings.
Hearing devices may
also be rated. 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 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 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 described
in the American National Standards
Institute (ANSI) C63.19 standard.
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Additional safety information