Hearing aids alone do not make listening easier in all situations. Background noise, distance, reverberation, and echo can all interfere with listening.
Babies and young children listen in difficult situations every day – listening in the car, at day care, and playing outside or at the park. FM systems are used to help overcome the challenges of listening in noisy places.
FM systems work like small radio stations. There is a small radio transmitter attached to a microphone and a small radio receiver. A parent or teacher wears the FM transmitter and microphone while the child wears the FM receiver. Listening to the FM signal is like listening to someone talking from only 3 or 6 inches away; even if that person is across the room.
The FM transmitter receives the signal from the microphone and then sends the low-power radio signal to the FM receiver. The receiver needs to be within about 50 feet of the transmitter to pick up the signal. The radio channels used by FM transmitters have been set aside for educational use in the United States.
The FM receiver gets the signal sent by the transmitter and sends it to a personal hearing aid, cochlear implant processor or other device.
In the past, FM systems were only used in schools to help students listen in noisy and reverberant classrooms. Now, many pediatric audiologists recommend that FM systems are also used at home.
Imagine a parent and child at home in the kitchen – while the parent is working at the stove or sink their back is turned to the child. However, if the child uses an FM system he or she can easily hear what the parent is saying, no matter the direction they are facing.
Additionally, FM systems keep the listening distance close no matter what the child is doing. Many families say that using an FM system at home gives them more opportunities to interact with their child in daily activities. Children report that using the FM system gives them a feeling of security when they are at a distance from their parents, such as in the grocery store or on a family outing. This may help children develop self-esteem and independence.
Some activities where FM systems work well are traveling in the car or van, visiting the zoo, playing in the park and shopping at the grocery store.
The car is a difficult listening situation – lots of background noise, the child cannot see the parent's face and there is added distance between the front and back seats. A hearing aid alone cannot overcome all these difficulties.
For families that spend a lot of time in the car, using an FM system provides a better communication connection between the parent and child.
A typical classroom has distracting background noises such as talking, paper rustling, shuffling feet, air-handling systems and audio-visual equipment. Most teachers move around the classroom or turn away from students when writing on a white board, causing the loudness of their voice to vary.
FM amplification systems will transmit the teacher's voice directly to the student at a constant level, insuring that their voice is heard above the background noise regardless of direction or distance from the student. Learn more about using assistive devices in the classroom.
There is a large variety of FM systems and options available for the classroom. Parents, the student, school personnel and the student's audiologist should work together to choose a system that will provide the most benefit and flexibility in the student's environment
Research shows that overhearing conversations helps children learn new words and improves their understanding of how to use language.
Parents need to decide when and how the FM system should be used. FM operation is controlled by a switch on the FM receiver or by remote control. There are different settings from which to choose when an ear-level FM receiver is connected to the child's hearing aid:
The FM microphone should be turned on when the parent is talking to the child in a noisy situation. It also should be turned on when the parent is going to be at a distance from the child, but wants the child to hear her voice at a stable level. The hearing aid microphone usually stays on so that the child can hear other sounds and voices around them. When the hearing aid is on, the child also can hear his own voice.
Buying an FM system for home use is an additional expense beyond personal hearing aids. An FM package, including the transmitter/microphone and ear-level receivers may cost around $2,500. If extra warranties or special microphones are needed, the cost may be higher. Parents often look for financial help to buy an FM system. Insurance policies often do not cover FM systems. Families should work with their audiologist to find funding.