An FM system is a type of wireless system that allows a hearing aid user to hear better in a noisy environment or when there is a large distance between a speaker and the hearing aid user. Typically, the speaker wears or holds a microphone that wirelessly transmits the sound of his or her voice to a receiever that is attached directly to the hearing aid.
An alternative to this arrangement is a microphone that is placed on a table in the middle of a group (such as in a meeting) to pick up sound from several speakers at once. This allows the hearing aid user to hear the speaker above any other noise that is present in the listening environment. This type of technology only works with behind-the-ear hearing aids.
Although FM systems are often used in conjunction with hearing aids, there are some systems that can be used by a person who has normal or near normal hearing, but has significant difficulty hearing in noisy situations.