A telecoil (sometimes coiled a t-coil or t-switch) is a very small coil of wire within the hearing aid that essentially functions as an antenna when it is activated. This antenna specifically picks up sound that is being broadcast as a magnetic signal, usually coming from a hearing loop or a hearing-aid compatible phone.
Because of the space that the telecoil takes up, they are currently only available in behind-the-ear (BTE) and in-the-ear (ITE) models. Hearing aids that contain telecoils
will have a switch to turn it on or off. With most models, turning on your telecoil means turning off the hearing aid’s microphone, so you’ll want to be sure to switch the telecoil off when you don’t need it. Using a telecoil with a hearing-aid compatible phone (many phones are hearing-aid compatible; you can check with your phone’s manufacturer if you’re unsure) can often eliminate feedback that some users experience when trying to
talk on the phone.
Hearing Loops ( Assistive Listening Systems) are common in many large public places, from theaters to airport terminals to churches. If you are in a place that has a hearing loop, you can turn on your telecoil and should be able to hear the public address system
Does My Hearing Aid Have a Telecoil?
Telecoils have been around for a couple decades, but they seem to be used much more commonly in Europe than in the US. Many people are even unaware that their hearing aid contains a telecoil, or if they do know about it, they may not understand the potential
benefits of using it. Check with you audiologist or dispenser.