Hearing aid compatibility involves two parts.

• Part One: The hearing aid side

  • To achieve hearing aid compatibility the hearing aid must be equipped with a telecoil, sometimes called a T-coil or T-switch. 

    • This is a small magnetic induction coil that is built into the hearing aid at the time of manufacturing. 

    • Generally when the hearing aid is switched to the "Telecoil" position the hearing aid microphone is turned off, preventing any chance of feedback, and the magnetic induction coil is turned on.  The only thing the person will hear is what is coming through the magnetic field. This limits the amount of acoustical clutter that interferes with speech clarity.

  • Most Behind-the-Ear hearing aids come equipped with a telecoil and is identified on the hearing aid switch by the middle "T" position were "T" stands for telecoil. 

  • Most In-the-Ear or Canal hearing aids the telecoil is an order option at the time the hearing aid is built and there is a special toggle switch mounted on the faceplate of the hearing aid. 

  • Generally if you have an In-the-Ear or Canal hearing aid and you have never been told about a telecoil then there is a very good chance your hearing aid does not have a telecoil.

  • Without a telecoil in your hearing aid it does not matter is the other part of the equipment is hearing aid compatible since it compatibility feature will not function with your hearing aid.

• Part Two: The external device

  • A compatible external device, telephone, FM receiver, TV listening device or other must be equipped with a way to generate a magnetic field that can be picked up by the telecoil in the hearing aid.

  • This is generally done by equipping the device with some type of induction loop that will generate a magnetic field.   The induction loop can be a wire loop built internally into the device, commonly found in telephone handsets, an external induction loop, like a neckloop or silhouette induction coil used with TV and FM listening devices or a room loop that is permanently installed in a room.

• Generally Assumptions:

  • If you have never been told about the telecoil and its function you most likely don't have one on your hearing aid.

  • With In-the-Ear hearing aids, the telecoil can sometimes be added by your dispenser if the aid is less than a year old.  Aids that are more than one year old generally can't be successfully upgraded because of the possibility of a technology mismatch between components.

  • With Canal and Completely-In-The-Canal hearing aids there is generally not enough room to mount a telecoil in the shell.  Please talk to you dispenser.

  • Telecoils in hearing aids can be used not just for the telephone but also as a way assistive listening devices can be coupled to a person's hearing aids. For this reason telecoils should be placed in both hearing aids since you want to feed sound into both ears.