How hearing aids work
Hearing aids are comprised of three parts: a microphone, an amplifier, and a speaker. The microphone picks up sound and converts it into an electrical signal, which the amplifier intensifies. The signal is converted back into an acoustic signal, which is then transmitted through the speaker.
Types of hearing aids
This is likely the style of hearing aid most people think of: part of the hearing aid fits snugly behind the ear and the other part of it fits just inside the outer ear. As technology has improved, BTE aids have become smaller and produce clearer sound.
This even smaller hearing aid fits completely inside the outer ear unlike the two components of BTE aid.
Because of their small size—even smaller than the ITE—this option isn’t appropriate for those with more severe hearing loss.

Analog or digital
In addition to size and placement, whether BTE, ITE or ITC, hearing aids can be either analog or digital. Both can be customized, but expect digital aids to cost more.
Your audiologist will also help you through the whole process of improving your ability to hear—from initial hearing tests, to selecting the appropriate style of hearing aid to customizing your aid and helping you adjust to them.