FM - Frequently Asked Questions

If you don’t find the answer to your general questions below, we encourage you to contact your local Phonak authorized hearing healthcare professional for more information.

Compatibility Issues

Is my hearing instrument compatible with Phonak FM?

Where can I see whether my hearing instrument is compatible with Phonak FM

Phonak MicroLink FM receivers are compatible with all Phonak Behind-The-Ear (BTE) instruments and most BTE instruments and cochlear implant speech processors from other manufacturers. The MyLink neck-loop FM receiver is compatible with any hearing instrument that has a T-coil, including custom made instruments. Click here, select brand and model and you can see whether your hearing instrument is compatible with Phonak FM.

FM Solutions/Products

Are digital hearing instruments enough?
My son has got digital hearing instruments. Does he still need an FM system?

Some users of digital hearing aids find that the sound quality has improved and the background noise reduced so that they no longer feel they need the assistance of a personal FM system. However, an FM system still has huge advantages in a classroom over digital hearing aids alone. Using the FM system reduces the effects of reverberation (echo) and distance between the teacher and child that are still difficult for a hearing aid alone to cope with. Have a chat with your teacher of the deaf about how your son manages with and without the FM system.

At what age should my child start using FM?
FM can be crucial to your child's development from a very early age. Experts recommend introducing the use of FM when the child starts being mobile.

My child wears two hearing aids, so should he wear two FM receivers?
The key advantage is achieved by providing your child with an FM system. Scientific evidence shows that transmission to both ears brings further significant benefits, and scientific data shows that speech understanding improved 40% when two FM receivers were used instead of one (Valente, Enrietto, Crandell, Lewis (2002)

FM with cochlear implants

My child has a cochlear implant. Is it possible to use Phonak FM systems with the cochlear implant?

Yes, that is possible. Individuals with cochlear implants experience the same difficulty as hearing instrument users in challenging listening environments. The Phonak miniaturized MicroLink receivers are therefore available in different configurations depending on the speech processor. Read >>more here about our FM solutions for CI recipients.

What is the difference between an FM System and an Infra-red system?
Infrared systems use infrared light to transmit the audio signal. When this light is blocked, the signal cannot be heard. Thus, infrared systems are susceptible to people and objects getting in the way. And, infrared systems do not work in sunlight.

FM systems can transmit through objects and operate as effectively in sunlight as they do indoors. FM systems require no installation.

Technical questions

Mixing new and old transmitters/receivers
Can I use the new inspiro transmitter in connection with the old MicroLink receivers?]

Yes, all Phonak FM receivers and transmitters (MicroVox, HandyMic, MicroLink, TelCom, Campus SX, inspiro etc.) are compatible with each other. But remember, the transmitter and receiver must be on the same channel/frequency.

How many receivers can be used with each transmitter?
Phonak transmitter broadcasts a radio signal into a given area. ANY receiver in that area can receive that signal. Thus, any number of receivers can be used.

Cochlear Freedom new "body-worn" version and FM
I have heard that Cochlear have a new "body-worn" version. Can someone tell me how to fit FM/MicroLink?

The Nucleus Freedom Mini BTE has a new battery pack with only two 675-batteries; If you wish to use FM, you need to use the body worn controller and the MLxi, MicroMLxS or MLxS. There is no MicroLink Freedom version with just two 675-batteries.

Safety and Health Questions

FM on airplanes
Is it safe (and legal) to use the Phonak FM system on an airplane?

The Phonak FM system is a radio system with both transmitter and receiver units and are therefore under the same restrictions during a flight as the cellular (mobile) phones. Consequently, a Phonak FM system cannot be used on a plane.

Use of FM in hospitals
I know that mobile (cellular) phones are not allowed in some areas of hospitals. What about my Phonak FM system?

The output power of the Phonak FM transmitters is very low and falls well within all government-established safety standards. Although we feel sure that you could use the Phonak FM system without any problems all over the hospital, we would recommend that you do not use it in the intensive care or the operation room. All other places it will be OK.

Pacemakers and FM
People with pacemakers are concerned about the use of FM systems. Can the transmitter influence the pace-maker?

Although, to our knowledge there are no cases reported for any interactions between FM and neck loops for hearing impaired and pacemakers or other medical devices, we think that it is our obligation as a manufacturer of electronic devices to inform our customers about the potential, in general, for electromagnetic interferences with medical devices. We therefore advise our customers with pacemakers or other medical devices to consult their physician or the manufacturer of their pacemaker or other medical device prior using Phonak FM transmitters (inspiro, EasyLink+, ZoomLink+, SmartLink+, etc.) or neck loop receivers (MyLink) in order to use these according to the safety recommendations of the physician who is responsible for their pacemaker (or medical device) or the pacemaker (medical device) manufacturer.
In addition, having in mind that the maximum output power level of typical Phonak transmitters (inspiro, SmartLink+, etc.) is less than 2 mW, which is 1000 times less than the maximum output power of a cell phone, we can specify that at separation distances of 5 cm, no interference should occur. The recommended distance is calculated according to table 204 from IEC 60601-1-2;2001.


Who pays for FM?
There are a number of laws that support provision of FM technology for children and adults with hearing loss. All of these laws arise from the perspective that as a society we will make buildings, programs and services accessible to people with disabilities. Such access is grounded in a civil rights framework and a set of laws that has been evolving in most countries over the past forty years.

In the US the Individuals with Disabilities Education Act (IDEA) requires that children with disabilities be provided with a free and appropriate public education that includes special education and related services. Most countries have similar laws.

We suggest that you contact your hearing care professional or local health department for further information. If you are unable to obtain financial help through your insurance or health department, there are some other public and private funding sources you can contact.


Can I use my FM system in other countries?
Phonak FM system is a radio device, and like any other radio, it communicates on specific channels. If you are travelling internationally, be aware that your channel may not be approved for use in all countries. Contact your hearing care professional for a list of approved countries where your Phonak FM system may be used.

Can I use more than one transmitter at the same time?
Yes, but only if you use the new Dynamic FM transmitter inspiro. The new inspiro transmitters include the revolutionary new MultiTalker Network feature, where up to 10 transmitters can be part of the network.

If you are using conventional transmitters it is not possible to let two transmitters/microphones operate on the same channel at the same time, as they will create interference between each other.

Interference Issues

Intermittency and short range
We have trouble with intermittency and short range. We would like some systematic way to determine if it is due to environment or truly a problem with the FM system itself.

If FM users are experiencing intermittency or short range, most of the time it is caused by interference in the form of signals generated by computers, electronic equipment and electrical appliances. Interference of this type occupies a wide band and can blank out an entire frequency spectrum. It only stops when the offending equipment is turned off. To check whether this is the problem, simply take the FM system outside the building to see if the interference disappears. If it disappears, switch off electrical equipment in the building one by one until the offending equipment has been found.
If a channel (frequency) is occupied by another FM user, the easiest way to avoid interference is simply to change the frequency of your FM system.

Static interference
Driving in a car I notice that power stations or high voltage lines create unwanted static in my FM system. Can something be done to avoid this static interference?

The FM receiver is not able to differentiate between the signal from your personal transmitter and the signal from a high voltage line on the same frequency. So there is unfortunately nothing you can do.

PC workstations and FM
A client tells me that he gets interference on one of the channels if he gets close to some (not all) PC workstations in their office. Have you heard reports of this before?

Yes, we have had a few reports about interference from PC workstations. There are some PC’s around that are not as shielded as they should be, and these PC’s can cause interference. If the FM system has to be used in close connection to a PC that causes interference, the best chance of getting rid of the interference is to try another channel (frequency)

Short operating range
We sometimes have customers who complain about reduction of the FM signal, once they leave the room where the transmitter is used. I know that signals can be reduced due to metal constructions, doors, etc, in between transmitter and receiver but I need more detailed data.

First of all, we have to remember that the MicroLink FM system is not a walkie-talkie system for communicating between two rooms. A MicroLink FM system is a wireless system that helps hearing instrument users in difficult listening situations. Listening situations where a normal hearing person can understand speech, but where the hearing instrument user cannot. Normal communication distance is typically within one room, and here the MicroLink system will typically have an operating range of 7 - 15 meters. In many instances it is possible to receive a signal from one room to the other, but as soon as the transmitter is in one room and the MicroLink receiver is in another room, we cannot always guarantee good reception, because there are so many things that can have influence on the FM transmission and some of those are not under our control.

The operating range also depends on the condition of the batteries in the FM transmitter/receiver/hearing instrument, as well as local interference and radio transmission conditions which may be affected by building design, metal walls, doorways etc.

So, a general guideline for how far the system should work? We would say: "Within a normal size room, - minimum 7 meters".

We are sure that in most cases the operating range will be much more than that.

Readings and resources

Where can I find articles and studies on the use of FM?
Many studies have documented the clear benefit of FM systems. Scientific studies and reports have covered various technical aspects, candidacy criteria, fitting related issues and outcome measurements.

Phonak offers you an extensive and growing collection of scientific publications on FM, from scientific magazines and many other sources from all around the world, as online pdf files. An easy to use search engine leads you quickly to the documents that you need. The convenient FM eLibrary can be found at