A hearing loop (sometimes called an audio induction loop) is a special type of sound system for use by people with hearing aids. The hearing loop provides a magnetic, wireless signal that is picked up by the hearing aid when it is set to ‘T’ (Telecoil) setting.
The hearing loop consists of a microphone to pick up the spoken word; an amplifier which processes the signal which is then sent through the final piece; the loop cable, a wire placed around the perimeter of a specific area i.e. a meeting room, a church, a service counter etc to act as an antenna that radiates the magnetic signal to the hearing aid.
Below is a diagram of a hearing loop at a shop counter or bank
Below is a diagram of a room hearing loop (e.g. at an event, place of worship etc)