A wire that circles* a room and is connected to the sound system. The hearing loop transmits the sound electromagnetically. The telecoil then picks up the electromagnetic signal in a user’s hearing instruments or a receiver with headphones.
Hearing loops can be permanently installed under the floor, in the ceiling, around a baseboard, or around an area in a room, or they can be temporarily placed around any area where people with hearing aids containing a telecoil might be.
There are also portable and permanently installed counter hearing loops.
In the United States, the preferred terminology is hearing loop vs. (audio frequency) induction loop. Rationale: 1) hearing loops are more user-friendly and more descriptive; 2) inductive loops are used to detect traffic and 3) IEC specification 60118-4 uses the term hearing loop.
*Depending on the room and design to meet the IEC standards, the wire may be configured in a snowman layout or phased array. See hearing loop diagrams.
