Hearing Aids and how they work
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Hearing Aids and how they work

What is a hearing aid?

A hearing aid makes sounds louder so that you are able to hear them. It is battery-operated and you usually put it in or around your ear. Hearing aids are available in different shapes, sizes and types. Not all hearing aids work in the same way although the principles are the same.

They all have a built-in microphone that picks up sound which is then processed electronically, either by analogue circuits, or digitally. The resulting 'signals' are then passed to a receiver, or earphone, in the hearing aid where they are converted back into sounds for you to hear.

The type of hearing aid you get will depend on your hearing loss and what you find comfortable.

A hearing aid won't give you perfect hearing. It will make sounds louder and clearer and may help you to hear on the telephone, make conversations easier and, as a result, increase your confidence when talking to other people.

A hearing aid will not make your hearing worse. If you have tinnitus – hissing, buzzing or other noises in your ears or head – you may hear it less when you use a hearing aid.

How to get a hearing aid?

The first thing you need to do is get your ears and hearing checked to confirm you have a hearing loss and to see if a hearing aid will help. Your hearing difficulty may need medical investigation and treatment so it is a good idea to see your GP (family doctor) first, even if you are thinking of buying a hearing aid privately.

How much do aids cost?

Hearing aids cost between £700 and 3,000 each. You should insure your hearing aid against loss, theft or damage.

Different types of hearing aids

Hearing aids are described as analogue or digital, depending on the technology they use to process sound. Digital hearing aids are the newest kind of hearing aid. The following types of aid are available as digital or analogue – except for body worn and bone conduction aids. We will advise you on the most suitable type for you. If you find it difficult to manage small or fiddly controls or equipment, you may find that you prefer to use the larger type of aids. However, some people find it easier to put an in-the-ear type of aid into their ear.

Behind-the-ear (BTE) hearing aids have an earmould, which sits inside your ear. The hearing aid rests behind your ear and a plastic tube connects it to the earmould. They are the most common types of hearing aid and most people who get NHS hearing aids have one of these.

In-the-ear (ITE) and in-the-canal (ITC) aids have their working parts in the earmould so the whole aid fits into your ear. They tend to need repairing more often than BTE aids. Some ITE aids can be seen from the side. The smallest in-the-canal aids fit right inside your ear canal, where they cannot be seen. If you have severe hearing loss, or very small ear canals, these aids will probably not suit you.

Bone conduction hearing aids (BAHA) are for people with conductive hearing loss or people who cannot wear a conventional hearing aid. They deliver sound through the skull by vibrations. One type involves a small operation behind the ear. To find out more about these click here

CROS/BiCROS hearing aids are for people with hearing in one ear only. CROS hearing aids pick up sound from the side with no hearing and feed it to the better ear. BiCROS aids amplify sound from both sides and feed it into the ear that has some hearing.

Waterproof and water resistant hearing aids have a thin membrane to help stop water getting into them. Waterproof aids are suitable for swimming and water-resistant aids can be used for other watersports.

Digital hearing aids

Digital hearing aids look just like modern analogue hearing aids but they are different because they process sound digitally using a tiny computer inside the aid. This makes it possible to process and customise sounds very precisely to suit your hearing loss and you can then listen to sound comfortably, whatever the pattern of your hearing loss. Many digital aids can be programmed with different settings for different sound environments that you can select at the touch of a button. Some adjust themselves automatically.

Can digital hearing aids help in noisy places?

One of the biggest problems for people with hearing aids is following what someone is saying in noisy places. Many digital hearing aids are designed to reduce steady kinds of background noise such as the rumble of traffic or the whirr of a fan. This makes listening more comfortable and can help you pick out one voice when many people are talking.

To help with this problem, many digital hearing aids use directional microphones to help you hear sounds best when they are directly in front of you so that you can focus on what you want to listen to. Most digital hearing aids have very effective feedback management systems to eliminate the past problem of whistling or howling.

How to use your hearing aid

Once you get your hearing aid, it is important to practise putting it in your ear and using the various controls. This will help you get used to it and get the most from it. First, check that the hearing aid fits snugly but comfortably.

Getting used to your hearing aid

It may take several months to get used to your hearing aid. Start by wearing it once or twice a day for short practise sessions around the house, gradually building up the length of time you use it. Listen to everyday noises such as the kettle boiling or doors opening and shutting to get used to how they sound. Then try conversations with one person, again in a quiet room. Make sure the other person sits facing the light as it will make it easier to lipread them.

Next, try conversations with two people or in small groups. Don't expect to hear everything that is said, but try to follow the conversation. When you have practised using your hearing aid indoors, try using it outside. To start with, be careful not to have the volume too high when you go out because sounds, such as traffic, can be loud.

Looking after your hearing aid

Behind-the-ear (BTE) hearing aids

Wipe the hearing aid and earmould with a dry tissue every time you take your hearing aid off. Ideally, you should wash the earmould and tubing every night. If you can't do this, wash them at least once a week. Only wash the earmould and tubing. Do not wash the hearing aid – the part that contains the battery.

Don't unscrew the elbow from the hearing aid. Instead, gently pull the plastic tubing off the elbow but not from the mould. Wash the earmould and tubing in warm soapy water, and rinse them.

Blow down the tubing to get the water out, and let it dry overnight. Once it is dry, push the end of the tubing back on to the elbow. The tubing will need changing every three to six months before it hardens or splits and causes problems.

In-the-ear (ITE) hearing aids

Custom ITE aids have only one part. If you bought an ITE hearing aid privately, it is likely to be a custom one. You must not wash these. Wipe them with a dry tissue and use a soft dry brush to remove wax from the opening. Do not poke anything into the opening as you may damage the earphone. These aids often come with instructions and cleaning tools to help you.

In-the-canal (ITC) and completely-in-the-canal (CIC) hearing aids

You must not wash these hearing aids. Wipe them with a dry tissue and use a soft brush to clean wax from the opening. ITC hearing aids often come with special instructions and cleaning tools.

Listening equipment

You can get a range of equipment to help you hear talks, conversations, or audiovisual equipment such as your television or stereo. Some of it is especially designed to be used with hearing aids on their 'T' setting.

Loop and infrared systems are often fitted in places such as theatres, public halls, post offices and banks. You can also fit them at home. Look out for a sign like this one.

Telephones described as 'hearing aid compatible' have a kind of built-in loop. When you use this kind of telephone with your hearing aid on the special setting, the sound you hear will be clearer and without background noise.

You can also use conversation aids, radio microphone systems and listening equipment with your hearing aids by plugging in a neckloop or earloop, and switching your hearing aid to the special setting.

When your hearing aid doesn't work properly

If you get no sound at all from your hearing aid or the sound is very faint you can check the following:

Is the battery working? Even if it is fairly new it can sometimes run down quicker than expected if you have accidentally left it on when not wearing it. You can buy battery testers so that you do not throw away good batteries unnecessarily. (See Hearing Aid Accessories).

If this is not the problem check that the sound outlet is not blocked with wax. If it is a Behind-the-Ear type look at the mould and either clean it using the tools provided or remove it from the hearing aid and wash it in warm soapy water, taking care to make sure it is completely dry before putting it back on the hearing aid. If it is an In-the-Ear instrument use the tools provided to clean it and if it is fitted with a removable wax guard try changing it to see if this restores the sound. Even when the hearing aid looks clean there can some times be small particles of wax or skin in the wax guard. Special cleaning fluids are also available (See Hearing Aid Accessories).

Whistling or squeaking is caused by 'feedback'.This happens when sound amplified by your hearing aid is fed back into it.

It may happen if:

  • You have not put the hearing aid in properly – push it gently to check.
  • You have excess wax in your ears – ask your GP to check your ears.
  • The hearing aid does not fit your ear closely enough. Put a little Vaseline on the mould to see if this helps by sealing the hearing aid in your ear. Be careful not to block the opening in the earmould as this will stop sound coming through.
  • You have the volume too high.