FM systems is a generic name to many solutions for hearing impaired
that rely on FM as the communication method (FM stands for Frequency
Modulation, which is a common and relatively simple Radio Frequency
protocol, exactly the same method they use on radio broadcast). It can
be used either with or without hearing
How it works
A typical FM system has two components: a transmitter and a receiver.
- The transmitter can have a microphone to receive the sounds, or
it can have some input jack that connects it to the sound source. The
later can be used, for instance, if you need to transmit sounds from a
- Some of the transmitters can be placed on a desk while others are
- The transmitter sends the sounds to the receiver using FM radio
The receiver receives the FM signals sent by the transmitter.
- If you use FM system with a neck loop receiver and hearing aids,
the receiver sends the sounds to your hearing aids using T-coil.
Meaning, you switch your hearing aid to T-coil mode, and the neck loop
sends the signals directly to the hearing aid.
- Another popular receiver is a small device, plugged as
a whole directly into your hearing aid. This is relevant for most BTE
devices since they usually have the port needed (named DAI, three holes
on the bottom of the hearing aid). It is sometimes called Audio
- In case you use it with no hearing aids, there are few
options of getting the sounds from the receiver to your ears. The
classic is using the headset the system comes with. You just put it
in your ears and hear whatever the Transmitter hears. Additional option
is to plug your own headset or earphones into the receiver.
FM Systems Usages
I like to divide the systems to personal and public.
To yours ears only, usually covers a small area. You can use it for
watching TV, listen to a teacher in a class where only you need and
In this case, there is one transmitter that broadcasts to a large
audience. It can be used on theaters, lectures, and more.
The idea is that anyone with the right FM receiver can hear whatever
the Transmitter sends over the air.
Just to give you a taste, here are
several examples and links to demonstrate few different FM systems.
- This page shows FM systems from different types. They show some
non-FM accessories on the same page too.
This is PHONAK web page that shows their FM transmitters.
And this the MLxi, a universal FM receiver by PHONAK, that
you can plug into a BTE device, in case it got a DAI port.
Important note and a disclaimer
I write this for the sake of hearing aids users that find themselves
confused by all the wireless terminology and misunderstandings.
Therefore, I try to keep things as simple as possible and I simplify
things to make them clearer. In addition, the discussion here is in the
context of hearing aids and hearing aids’ users. I don’t try to cover
the entire wireless world here, and therefore, all the data is observed
from the angle of a hearing aid user and for his/her benefit.