Huawei M735 User Manual page 58

T-Ratings: Phones rated T3 or T4 meet FCC requirements and are likely to
be more usable with a hearing device's telecoil ("T Switch" or "Telephone
Switch") than unrated phones. T4 is the better/higher of the two ratings.
(Note that not all hearing devices have telecoils in them.) Hearing devices
may also be measured.
Your phone meets the M4/T3 level rating.Hearing devices may also be
rated. Your hearing device manufacturer or hearing health professional
may help you find this rating.
For more information about the FCC Hearing Aid Compatibility please go
to http://www.fcc.gov/cgb/dro.
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