Samsung Chrono SCH-R260 User Manual page 234

T3 + T2 = 5
M3 + M2 = 5
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.
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