A hearing aid is basically a miniature public-address system. Its key components are:
Hearing aids can be categorised in many ways. The simplest way to categorise them is by the place in which they are worn.
Behind the ear (BTE)
A behind-the-ear (BTE) hearing aid is a two-piece hearing solution. The microphone, electronics and receiver are mounted in the characteristic banana-shaped case, and the sound is passed via a tube to a custom earmould. Recent developments have led to the introduction of open-mould and receiver-in-the-ear which allow for more comfort and better sound.
Siemens BTE and Life Multi-language user guides
In the ear (ITE)
The next smallest type is the in-the-ear (ITE) hearing aid. These vary in size from full concha styles that, as their name implies, fill the entire concha (ear) as well as about half the length of the ear canal.
Siemens ITE Multi-language user guides
In the canal (ITC)
When an ITE hearing aid occupies a sufficiently small portion of the ear, it is referred to as an in-the-canal (ITC) hearing aid.
Completely in the canal (CIC)
Hearing aids that fit entirely within the ear canal are known as completely-in-the-canal (CIC) hearing aids. These hearing aids use small componants and do not protrude into the outer ear.
The typical locations of the major components within a BTE and ITC hearing aid are shown below.