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This is written for deaf and hard of hearing
people who would like to find out more about digital hearing aids.
Read this factsheet to find out about:
     
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.
Open Fit hearing aids
Also known as 'Over the Ear' (OTE), these are discreet
aids that fit over the ear and are connected by a fine clear tube
to the almost invisible section that fits inside the ear canal.
They are beneficial for high frequency hearing loss and reduce the
'occlusion effect' - the amplification of your own voice when you ears are plugged up.
Completely in the Canal hearing aids (CIC)
This is custom made to fit right inside the ear canal
and is almost impossible to see. Although they are suitable for many
people, your hearing aid Dispenser will be able to advise you on their
suitability for you once you have had your hearing assessed.
The close proximity to the eardrum gives sound a natural boost in volume.
In the Canal hearing aids (ITC)
These also fit in the ear canal but are slightly larger than the CIC aids
with some of the aid visible outside the canal. Like CIC aids, they offer a
natural sound reception. They are suitable for mild to moderately severe hearing loss.
In the Ear hearing aids (ITE)
These are suitable for a wide range of hearing loss and are easy to handle and adjust.
They fit the entire area of the inner ear which enables them to hold a larger amplifier
and more features.
Behind the Ear hearing aids (BTE)
The aid is behind the ear with a thin plastic tube connecting to a custom-made
section that fits into the entrance to the ear. The electronics are in the case that
fits behind the ear. BTE hearing aids are suitable for all types of hearing loss and all ages.
Receiver in the Canal (RIC)
One of the most popular hearing aids styles available today, this device is small,
discreet and incredibly quick to fit. With the receiver directly in the ear canal,
it enhances both comfort and sound quality. This type is perfect for many
first-time users.
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.
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How do 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.
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How do 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
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 but they
provide a dramatic improvement over analogue hearing aids
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.
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 give as comfortable listening 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 but your hearing aid dispenser will advise you of the options
available.
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 your hearing loss
is the most important factor in which type of hearing correction
system will be best suited for your needs.
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What sort of digital hearing aids are available
on the 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
Information
Line or Modernising Hearing Aid Services.
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.
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.
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Buying abroad
You may have read about buying hearing aids abroad at lower prices,
particularly in Germany and Denmark. 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.
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