Hearing loop, or induction loop systems utilize electromagnetic energy to transmit sound directly to your hearing aid. They consist of a sound source (public address systems are popular), an amplifier, a loop of wire and a receiver or telecoil (t-coil), a tiny wireless receiver built into many devices. When you are in close proximity to the loop, you will receive clear sound free of background noise. Hearing loops can be connected to all types of audio sources, and are often set up in public facilities such as airports, churches and lecture halls.