User Guide

Managing Your Phone 20
HAC Rating
The FCC has created a rating system for cellular phones regarding their HAC-related
performance. This rating helps consumers with hearing disabilities to find phones that will work
well with their hearing aid devices. The HAC rating and measurement procedure are described
in the American National Standards Institute (ANSI) C63.19:2007.
ANSI C63.19 contains two rating standards: an “M” rating from 1 to 4 for hearing aids operating
in microphone mode, and a “T” rating from 1 to 4 for hearing aids operating in telecoil mode.
M-Rating stands for Microphone rating and indicates the amount of reduction of RF interference
between the telephone and the hearing aid in acoustic coupling mode (also called microphone
mode).
Phones rated M3 or M4 meet FCC requirements and generate less interference to hearing
devices set in microphone mode. T-Rating stands for telecoil rating and represents inductive
coupling with hearing aids that are operating in telecoil mode. A telecoil is a small piece of
tightly wrapped wire, built into some hearing aids. While the microphone of a hearing aid picks
up all sounds, the telecoil will only pick up an electromagnetic signal from the telephone. Thus,
users of telecoil-equipped hearing aids are able to communicate over the telephone without the
amplification of unwanted background noise.
Phones rated T3 or T4 meet FCC requirements and generate less interference to hearing
devices set in telecoil mode.
A combination of M-rating and T-rating defines the final HAC rating and is a deciding factor in
selecting cellular phones for people with hearing problems. A HAC compliant phone could be
rated:
● M3/T3
● M3/T4
● M4/T3
● M4/T4
These ratings assist hearing device users to find phones that are compatible with their hearing
devices. Ratings are shown on the phone‟s box or label. The ratings are not guaranteed for
suitability. The results vary depending on the individual‟s hearing loss and the immunity
characteristics of the used hearing device, i.e. its resistance to interference. The best way to
evaluate the suitability of the phone is to try it with the intended hearing aid device.
Sonim XP3410-A-R1 has been tested for hearing aid device compatibility and complies with the
Federal Communications Commission (FCC) requirements. Sonim XP3410-A-R1 is rated
M4/T3.