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.
When you're talking on a cell phone, it's recommended that you turn the BT
(Bluetooth) or WLAN mode off for HAC.
For information about hearing aids and digital wireless phones
Wireless Phones and Hearing Aid Accessibility
http://www.accesswireless.org/
Gallaudet University, RERC
http://tap.gallaudet.edu/Voice/
FCC Hearing Aid Compatibility and Volume Control
http://www.fcc.gov/cgb/dro/hearing.html
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
For Your Safety
116