Telecoils

A Telecoil, T-Coil or T-Switch is a feature that enables the hearing aid to be used with a hearing aid compatible phone and other assistive listening devices. When the telecoils are turned on they pick up an electromagnetic field created by a compatible phone or a neckloop 'coupler' used in an FM signal and converts these signals to sound by the hearing aid. On the positive side a telecoil will avoid feedback from a normal telephone and exposure to over-amplification. On the negative side a telecoil can pick up unwanted electromagnetic sources such as computer monitors, airplanes, digital mobile phones, and even heavy machinery. Sound from a telecoil is amplified and initially will not sound normal. Proper positioning of a telecoil is important for the smaller canal and in-the-ear (ITE hearing aids) due to their small size. Users must also remember to turn them off when not in use because environmental sounds will be shut out making the user think the device is not working properly.