For Your Safety 173
In the above example, if a hearing aid meets the M2 level rating and the wireless
device 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 device. “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 device is maintained,
secondary transmitters such as Bluetooth® and WLAN components must be
disabled during a call.
For information about hearing aids and digital wireless devices:
Wireless Devices and Hearing Aid Accessibility
http://www.accesswireless.org/
Gallaudet University, RERC
http://tap.gallaudet.edu/Voice/
FCC Hearing Aid Compatibility and Volume Control
https://www.fcc.gov/general/hearing-aid-compatibility-and-volume-control
The Hearing Aid Compatibility FCC Order
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-03-168A1.pdf
Hearing Loss Association of America [HLAA]
http://hearingloss.org/content/telephones-and-mobile-devices
Caution! Avoid Potential Hearing Loss
Prolonged exposure to loud sounds (including music) is the most common
cause of preventable hearing loss. Some scientific research suggests that using
portable audio devices, such as portable music players and cellular telephones,
at high volume settings for long durations may lead to permanent noiseinduced
hearing loss. This includes the use of headphones (including headsets, earbuds and
Bluetooth or other wireless devices). Exposure to very loud sound has also been
associated in some studies with tinnitus (a ringing in the ear), hypersensitivity to
sound and distorted hearing. Individual susceptibility to noise-induced hearing loss
and other potential hearing problems varies.
