Health and Safety Guide

Health and Safety Information 49
this rating. Higher ratings mean that the
hearing device is relatively immune to
interference noise.
Under the current industry standard,
American National Standards Institute
(ANSI) C63.19, the hearing aid and
wireless mobile device rating values are
added together to indicate how usable
they are together. For example, if a
hearing aid meets the M2 level rating
and the wireless mobile device meets
the M3 level rating, the sum of the two
values equals M5.
Under the standard, this should provide
the hearing aid user with normal use
while using the hearing aid with the
particular wireless mobile device. A sum
of 6 or more would indicate excellent
performance.
However, these are not guarantees that
all users will be satisfied. T ratings work
similarly.