Sound is a type of energy made by vibrations. Using pressure, waves emit through the air. Whenever someone speaks, their voice box makes vibrations that go up through their throat, and into other peoples ears. It vibrates the ear drum, which then goes into the brain, and allows humans to hear.

Hearing loss is normally caused by a problem in your ear. It can be a problem with your outer, middle or inner ear. Some people are born with hearing loss. Other people develop hearing loss later because of a health condition. The most common causes are aging and being exposed to loud noise.

The most common hearing device types are in the canal (ITC) and behind the ear (BTE). By far, the most used type is BTE, as both hearing aids and cochlear implants are BTE. Different types of hearing devices suit different peoples hearing needs.