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This factsheet is part of RNID's hearing aids range. It is written for deaf and hard of hearing people who would like to know more about digital hearing aids.
Read this factsheet to find out:
Hearing aids can be described as either analogue or digital, depending on the technology they use to process sound. Digital hearing aids are the newest kind of hearing aid. In fact, analogue technology is gradually being phased out. However, body-worn aids and some bone conduction types are analogue and will continue to be available. Your audiologist or hearing aid dispenser will advise you on the most suitable type for you.
These usually have an earmould that 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 NHS digital hearing aids are BTE aids.
There is a new, alternative way of fitting BTE aids that does not involve an earmould. This is called an ‘open ear fitting’ and uses a smaller, soft earpiece at the tip of the tubing instead of an earmould. These fittings can be less visible than earmoulds but are only suitable if your hearing loss is mild or moderate. They can give you a very natural sound.
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 ITC aids fit right inside your ear canal, where they can hardly be seen at all. If you have a severe hearing loss, or very narrow ear canals, these aids will probably not be suitable for you.
These have a small box that you can clip to your clothes or put in your pocket. This box 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.
These are for people who cannot wear a conventional hearing aid or those who have a conductive hearing loss. Conductive hearing loss happens when sound vibrations are unable to pass freely through the outer and middle parts of your ear. Instead of sound from the hearing aid going into your ear canal, bone conduction hearing aids send sound vibrations through the skull, directly to your inner ear. This is done by wearing a headband that holds a small bone vibrator in place behind the ear.
Another type, called a bone anchored hearing aid (BAHA), involves having an operation behind your ear to implant a permanent fixture in the bone, which removes the need for wearing a headband. A small sound processor clips onto this fixture.
See our factsheet Bone conduction hearing aids (external link, opens new browser window) for more information.
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 hearing 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.
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) and fed to the earphone on the hearing aid so you can hear them.
Most of the better analogue hearing aids use ‘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. But analogue hearing aids don’t have all the features that come with advanced digital aids, and can’t usually be set to suit your individual hearing loss very precisely.
Digital aids work in a different way. They take the signal from the microphone and convert it into ‘bits’ of data – numbers that can be manipulated by a tiny computer in the hearing aid. This makes it possible for the hearing aid to process sounds in ways that are impossible with analogue aids. It also means that the person fitting the hearing aid can tailor the sound very precisely to suit you.
The more advanced 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.
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 can make listening more comfortable. But it does not necessarily help you to pick out a single voice from everything else going on, especially when several people are talking at once.
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 directional microphones.
Directional microphone systems amplify sounds that come from in front of you more than sounds to the side or behind you. This makes it easier for you to focus on what you want to listen to in a noisy place. Most digital hearing aids have microphones that can be set to operate like this. This means you can switch between directional and all-round sound, depending on what you need to hear at the time. Some digital aids will detect where the noise is coming from and automatically adjust to reduce the noise selectively. However, a hearing aid cannot know what you want to listen to and so the reduction of unwanted sound can never be perfect.
Yes. Some digital hearing aids have feedback management systems. This means that they can automatically detect any feedback and try to reduce the whistling that bothers many people who use hearing aids.
Most digital hearing aids have some form of loudness compression system. This means the hearing aid can manage sounds of different volumes and only amplify them as much as you need. 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.
It will only work well for you if the person who fits it also adjusts the settings carefully to suit you, when you first have it. You may need to have your aid fine-tuned again, when you get used to it.
It is usually possible to switch to the ‘T’ (telecoil) setting with a digital hearing aid, as it is with an analogue aid. The telecoil is a small component in the aid that picks up signals from a loop system or hearing aid compatible telephone. But your audiologist will need to programme the ‘T’ setting and show you how to switch over. If you choose a very small style of hearing aid that fits into your ear canal, there might not be room for a telecoil, so you won’t have the ‘T’ option.
For more information, see our factsheet Loop and infrared systems - for deaf and hard of hearing people (external link, opens new browser window).
They are not necessarily smaller than analogue hearing aids. Digital hearing aids – just like analogue ones – come in BTC, ITE or ITC styles. You may be offered a choice if you go to a private hearing aid dispenser. 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 What are the different types of hearing aid? for more information about different types of hearing aid.
At RNID, we campaigned successfully for the modernisation of NHS hearing aid services and the provision of high quality digital hearing aids. From 2000 to 2005, we worked with the Department of Health to lead a £125m modernisation programme in England, which is now complete. Similar audiology modernisation has taken place in Wales, Scotland and Northern Ireland.
If you have not had an NHS hearing aid before, you must first visit your GP. All audiology departments should be offering digital aids to every patient waiting for their first hearing aid, if their hearing tests show that they would benefit from one. You should be offered two digital hearings aids if appropriate, one for each ear. If you are given two, it’s worth trying them both together, 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.
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.
Follow-up service on the NHS
Yes, it’s possible to buy digital hearing aids from high street dispensers, but the cost of buying them privately is very high – up to £3,500 for each aid. See our factsheet Buying a hearing aid? (external link, opens new browser window) for more information.
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.
Our Information Line offers a wide range of information on many aspects of deafness and hearing loss. Contact us for further copies of this factsheet and our full range of information factsheets and leaflets. You can also contact us if you would like information in Braille, on audiotape or large print.
RNID Information Line
19-23 Featherstone Street
London EC1Y 8SL
Telephone 0808 808 0123
Textphone 0808 808 9000
Fax 020 7296 8199
Email: informationline@rnid.org.uk
RNID Information, May 2007