All hearing aids work through a similar mechanism — sounds are picked up by a built-in microphone and then converted into signals which are then amplified digitally. These signals are then converted back into sounds within the receiver of the hearing aid.

Just as glasses cannot fully restore sight, hearing aids cannot fully restore hearing loss. However, what they can do is significantly improve the quality of life of the hearing impaired, making it possible to take part in daily activities, such as being involved in conversation, talking on the telephone or simply watching television.

Hearing aids can be worn in one ear (monaural) or in both ears (binaural). Many people have found that wearing binaural aids significantly increases the effectiveness of their hearing devices.

Digital hearing aids can be customised so that they closely match an individual’s hearing loss pattern and can also offer different programmes for different environments.

There are a number of different types of hearing aids. These include:

	In-the-ear (ITE)
		Suitable for a wide range of hearing loss. All components are housed in a plastic shell which fills the outer ear.
	Behind-the-ear (BTE)
		Suitable for all types of hearing loss. Electrical components are housed in a case which fits behind the ear; plastic tubing transmits sound from the hearing aid to the earmold and subsequently the ear drum.
	Completely-in-the-canal (CIC)
		Suitable for mild to moderate hearing loss. These aids fit into the ear canal.

The introduction of Oticon Delta has created a new category of hearing solutions called RITE (Receiver In The Ear), merging the cosmetic advantages of in-the-ear instruments with the technological possibilities of behind-the-ear instruments.