Practical Hearing Aid Information


Practical Hearing Aid Information | Private hearing aids 

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, which are analogue only. Your audiologist or hearing aid dispenser will advise you on the most suitable type for you.

Behind-the-ear (BTE) hearing aids

These have an earmould which sits inside your ear. The hearing aid rests behind your ear and a plastic tube connects it to the earmould. This is the most common type of hearing aid: most people with NHS hearing aids have one of these.

In-the-ear (ITE) and in-the-canal (ITC) aids

These have their working parts in the earmould, so the whole aid fits into your ear. They tend to need repairing more often than behind-the-ear aids. Some in-the-ear aids can be seen from the side. The smallest in-the-canal aids fit right inside your ear canal, where they can't be seen at all. If you have severe hearing loss, or very narrow ear canals, these aids will probably not suit you.

Body-worn hearing aids

These have a small box that you clip to your clothes or put in your pocket. This contains the microphone and working parts. It is connected by a lead to an earphone clipped into your earmould.


Body-worn hearing aids may be suitable if you have sight problems, or problems using very small switches or buttons. Some models are very powerful.

Bone conduction hearing aids

These are for people with conductive hearing loss, or people who can't wear a conventional hearing aid. They deliver sound through the skull by vibrations. A bone conduction hearing aid can be fitted to a special headband or built into spectacles. Another type, called the bone anchored hearing aid (BAHA), involves having a small operation behind the ear.

Contralateral routing of signal (CROS) and BiCROS hearing aids

These are for people with hearing in one ear only. CROS hearing aids pick up the sound from the side with no hearing and feed it to the better ear. This ensures that you don't miss sounds on your deaf side. BiCROS aids amplify sound from both sides and feed it into the ear that has some hearing.

Disposable hearing aids

These are only suitable for people with mild to moderate hearing loss. Disposable hearing aids fit right inside the ear canal, but they may not be comfortable for everyone because they only come in fixed sizes. They can be thrown away and replaced with a new one when the battery runs out, which is usually after about 10 weeks. You can buy them from some branches of Boots, the high-street chemist.

Waterproof and water-resistant hearing aids

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

How analogue hearing aids work

Analogue hearing aids have a microphone that picks up sound and converts the sound into small electrical signals. These signals vary according to the pattern of the sound. The signals are then amplified (made louder) by transistors and fed to the earphone on the hearing aid so you can hear them.


Most of the better analogue hearing aids compress the sound using 'automatic gain control' (AGC). This amplifies quiet sounds until they are loud enough to be heard, but gives less amplification to sounds that are already loud, so you're protected against uncomfortably loud sound levels. Analogue hearing aids don't have all the features that come with advanced digital aids, but they are the least expensive hearing aids available.

How digital hearing aids work

Digital aids work in a different way. They take the signal from the microphone and convert it into 'bits' of data; that is, numbers that can be manipulated by a tiny computer in the hearing aid. This makes it possible to tailor and process sounds very precisely, in ways that are impossible with analogue aids. The better digital aids can be very finely adjusted to suit your individual needs. You may also be able to switch between different settings suitable for different listening conditions. Many digital aids even adjust themselves automatically to suit different sound environments.

Cutting out background noise

When someone talks to you, you usually want to hear what they are saying, rather than whatever noise is going on in the background. People who use traditional analogue hearing aids often complain that they find it difficult or impossible to follow conversations in noisy places. Many digital 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. But it does not necessarily help you to pick out a single voice from everything else that's going on, especially when several people are talking.


Two things have been shown to improve hearing in noisy situations more than anything else: wearing hearing aids in both ears, and using hearing aids that have twin microphones.

What are twin microphones?

'Twin' or 'dual' microphones are a type of directional microphone. The twin microphone picks up sounds that come from in front of you much better than sounds to the side or behind you, making it easier for you to focus on what you want to listen to in a noisy place.


Some digital hearing aids have twin microphones. This means you can switch between directional and all-round sound, depending on what you need to hear at the time.

Can digital aids help reduce whistling?

Yes. Some digital hearing aids have 'acoustic feedback suppression' or, better still, 'feedback cancellation'. This means that they can automatically reduce the whistling that bothers many people who use hearing aids.

More comfortable listening

Many digital hearing aids have a feature called 'wide dynamic range compression' that can be adjusted separately in each of several 'bands' or 'channels'. It means the aid can be programmed to suit your particular hearing loss and ensures that you always hear different sounds at levels that are comfortable for you. This type of aid is often completely self-adjusting. But it will only work well for you if the person who fits it also adjusts the settings carefully when you first have it. You may need to have your aid fine-tuned again when you get used to it.


Some types of analogue aid can also be programmed to suit individual users, but the way loudness is controlled in these aids is less sophisticated than in multi-channel digital aids. These types of aid may not always make listening as comfortable as digital aids.

What is the "T" setting?

It's usually possible to switch to "T" with a digital hearing aid, as it is with an analogue aid. But your audiologist will need to set this up and show you how to switch over. The "T" setting allows you to pick up sound from a loop system or inductive coupler. But if you choose a very small style of analogue or digital aid that fits into your ear canal, there might not be room for a telecoil, so you won't have the "T" option.

What size are digital hearing aids?

Digital hearing aids just like analogue ones come in 'behind-the-ear', 'in-the-ear' or 'in-the-canal' models. They are not necessarily smaller than analogue hearing aids. You may be offered a choice but remember that the very small models, though less noticeable, may be more fiddly to use, tend to break down more often and you may not be able to use them with a loop system. But some people find them easier to put in and take out. See this section "Different types of hearing aids" .

What sort of digital hearing aids are available on the National Health Service (NHS)?

You can now get NHS digital hearing aids in many parts of the UK. To find out which NHS trusts and audiology departments are part of the modernisation programme, contact the RNID Information Line or Modernising Hearing Aid Services. You may also want to look at this link "The National Health Service hearing aid service".

Both moderate-power and high-power digital hearing aids are available for adults and children. They are sophisticated multi-channel aids with features such as directional microphones and automatic noise reduction.

Who can qualify for a digital aid?

If you have not had an NHS hearing aid before, you must first visit your GP. The modernised audiology departments are offering digital aids to every patient waiting for their first hearing aid, if their hearing tests show that they would benefit from one. You may be offered two digital hearings aids, one for each ear. If so, it's worth trying them both, because many people benefit more from an aid in each ear than from just one.

Audiology departments will also offer digital aids to people who already have NHS analogue aids, if they're reassessed and found to need new aids.

If you're a war pensioner, you'll be given priority for hearing aids if your pension was awarded for deafness resulting from service. This means that you may be seen more quickly at your clinic but it does not mean that you are entitled to better hearing aids than other patients. If your local clinic is already part of the modernisation programme, you will probably be able to try digital hearing aids.

You can get an NHS digital hearing aid even if you've already bought a hearing aid privately. If you're a private ear, nose and throat (ENT) patient, you must wait the same amount of time to be fitted with an aid as NHS patients referred by their GP. You will not be given any priority over other referrals.

Who will not be eligible for a digital aid?

You will generally not be eligible to get digital aids if you've been fitted with a new hearing aid within the last three years, unless your hearing has become significantly worse since then.

If you already have an NHS hearing aid, you should wait to be invited for a review appointment. But you should ask for an appointment if you're having real difficulties with your aid, or if you think that your hearing has become worse.

If you are an overseas patient, as defined by the NHS rules, you will not generally be eligible to be fitted with digital aids.

It's very unlikely that hospitals will accept patients from outside the areas they normally provide a service for. Many already have long waiting lists and demand is increasing all the time.

Follow-up service on the NHS

You will be given a follow-up appointment if you get digital aids on the NHS.

Batteries and hearing aid repairs are available free of charge. NHS hearing aids remain government property, so you can't insure them on your household insurance policy. And you should return the aids to your audiology department if you no longer need them.

If you lose or damage a digital hearing aid, you may sometimes be charged or have to accept an analogue aid as a replacement.

How to buy digital hearing aids privately

It is possible to buy digital hearing aids from high street dispensers, but the cost of buying them privately is very high; up to £2,500 for each aid. If you choose to buy privately, you'll want to be sure that what you're getting is right for you. See our factsheet "Buying a hearing aid?" for more information.

Buying abroad

You may have read about buying hearing aids abroad at lower prices, particularly in Germany and Denmark. RNID can't recommend any particular hearing aid models, manufacturers or services. We would advise you to think carefully before buying a hearing aid abroad.

The initial cost of buying a hearing aid abroad may be less than in the UK, but you may need to see the dispenser for adjustments sometimes several times which could be expensive and inconvenient. Before you buy, it's important to check what will happen if you need more help, or if your hearing aid breaks down once you are back home.

Useful organisations

The Modernising Hearing Aid Services website (external link, opens new browser window) can give you more information about the NHS sites which now fit digital hearing aids.