Hearing Aids

Hearing aids assist people of all ages to hear, and cover a wide range of hearing loss, either in one or both ears. This page explains how they work and the different types available - see also the cost of hearing aids and financial assistance.  See also our policy on the sale of hearing aids online.

How do hearing aids work?

In all hearing aids, sound enters a hearing aid through a tiny microphone.  The sound is then processed, amplified and then delivered via a receiver (loudspeaker) to your ear canal.

Hearing aid technology is constantly changing and the wide array of choices can sometimes be confusing.  

Hearing aid technology advanced dramatically in 1996 when the world’s first 100% digital hearing aid was produced. Today, in many ways, hearing aids today bear little resemblance to those of a decade ago.

People who have put them aside in the past because of dissatisfaction, find that major advances have increased user satisfaction enormously - from the size and shape, to the power of amplification and processing of sound.

Choosing a hearing aid

Just as every person and every ear is individual, so is the hearing loss itself. The wide range of high quality hearing instruments offer individual solutions for real people, living real lives.

Before choosing a hearing aid there are a number of factors to consider

  • The most important function of your hearing aid is to compensate for your hearing loss
  • Your hearing care professional will be able to recommend a solution, and help you make the right choice
  • The solution should perfectly match the degree of hearing loss, the level of experience with hearing aids, the lifestyle and financial circumstances of each individual

  

Sizes and shapes


Completely-in-the-Canal (CIC): These are the smallest type of hearing aid made, and are almost invisible in the ear. All the components are housed in a small case that fits far into the ear canal. CICs are custom made for each ear and use a very small battery that requires good manual dexterity. This type of hearing aid is not suitable for people with severe hearing loss.

In-the-Canal Hearing Instruments (ITC):  This type also fits far into the ear canal. Canal hearing aids use a slightly larger battery than the CIC style. This style is used for mild to moderate hearing loss.

In-the-Ear Hearing Instruments (ITE):  ITEs can be used for a wider range of hearing loss. Due to their larger size, they can accommodate larger sound amplifiers and more features such as a telephone switch. They are also easier to handle.

Behind-the-Ear Hearing Instruments (BTE):  In this style of hearing aid, the electronics are held in a case that fits behind the ear. Tubing and a custom made ear mould direct the sound to the ear canal. The robust design makes this the style recommended for children. BTE hearing aids can provide more amplification than smaller devices due to the stronger amplifier and the larger battery. This style is available in several colours for hair and skin tone matching, plus bright, fun colours for children.

Analogue versus digital hearing aids – what’s the difference?

In all hearing aids, sound enters through a microphone, is processed and amplified and then delivered to a receiver (loudspeaker). This sends the output either directly to the ear canal of the user, or via tubing to an ‘ear mould’ and into the ear canal.

Analogue:  Analogue sound processing basically means that the movements in the air which make up sound are translated into one unified, but complex, electrical current by a microphone. Analogue sound is like making a photocopy - the sound is registered and you get an overall picture. But the actual processing is like receiving a photocopy - it can only be done to a certain extent because it causes a deterioration of the original imprint.

Digital:  With Digital sound processing, the sound is registered mathematically. It is encoded as a series of numbers that measure its pitch and volume at a given instant in time. Processing the sound bit by bit is much more precise, and certain details can be changed without affecting the general picture. Being more robust than an analogue signal, a digital signal can be repeated accurately and endlessly without affecting the overall quality. It's like making copies of a scanned image on a computer: each copy is a perfect duplicate of the original.

See also: the cost of hearing aids and financial assistance for hearing aids.

If you think you may need a hearing aid, consult your doctor, your local branch of the Hearing Association, or an audiologist. Also, try our Test Your Hearing quiz.

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