Hearing aid

Hearing aid: An instrument to help in hearing. There are four common styles of hearing aids.

From largest to smallest, they are: Behind-the-ear (BTE) hearing aids, In-the-ear (ITE) hearing aids, In-the-canal (ITC) hearing aids, and Completely-in-the-canal (CIC) hearing aids.

There is also a body hearing aid for very severe hearing loss. In general, hearing aids should ideally be binaural (in both ears), if the hearing loss involves both ears.