There are four fundamental tyles of hearing aids. The styles differ by size, their placement on or inside the ear, and the degree to which they amplify sound. The styles are as follows:

Behind-the-ear (BTE)

BTE hearing aids consist of a special plastic case worn behind the ear and connected to a small earmold that fits inside the outer ear. The electronic parts are held in the case behind the ear. Sound travels from the hearing aid through the earmold and into the ear. BTE aids are used by people of all ages for mild to profound hearing loss and are available in a variety of styles, features and colors (to match hair color)..

A new version BTE aid is the so-called "open-fit hearing aid". These small hearing aids fit behind the ear completely, with only a narrow tube inserted into the ear canal, enabling the canal to remain open. In addition, some people may prefer the open-fit hearing aid sound quality.

In-the-ear (ITE)

All parts of the aid are contained in a shell that fills in the outer part of the ear. These aids are larger than canal aids and, for some people, may be easier to handle than smaller aids

In-the-canal (ITC)

The ITC hearing aid is made to fit the size and shape of a person's ear canal and the majority of the hearing aid is positioned in the ear canal.  They are often smaller and less obtrusive than ITE hearing aids.

Completely-in-canal (CIC)

The CIC hearing aid is almost completely hidden in the ear canal. Both ITE and ITC are generally used for mild to moderately severe hearing loss.

Because they are small, canal aids may be difficult for a person to adjust and remove. In addition, canal aids have less space available for batteries and additional devices, such as a telecoil. They usually are not recommended for young children or for people with severe to profound hearing loss because their reduced size may limit their power and volume.