Safety Guidelines
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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 hearing 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’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.
When you’re talking on a cell phone, it’s
recommended that you turn the BT (Bluetooth)
mode off for HAC.
For information about hearing aids and digital
wireless phones
Wireless Phones and Hearing Aid
Accessibility
http://www.accesswireless.org/Home.aspx
FCC Hearing Aid Compatibility and Volume
Control
http://www.fcc.gov/cgb/consumerfacts/
hac_wireless.html
