Samsung SCH-R335MSATRF - Manual (Page 99)

Health and Safety Information 90
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 is
synonymous for T ratings. 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.
M3 + M2 = 5 T3 + T2 = 5