Questions and Answers Booklet
Introduction
This booklet aims to answer some of your questions about cochlear implants. Write down any
additional questions you have as you think of them, and they can be answered when you come to the
clinic.
Contents
1 The ear ....................................................................................................................................1
2 Cochlear implants ....................................................................................................................1
3 The Cochlear Implant Programme ..........................................................................................3
4 Experience of cochlear implant users .....................................................................................5
5 Cochlear implants in children ..................................................................................................6
6 Research aspects ............................................................................................................... 7
1 The Ear
How does the ear normally work?
In a healthy ear sound travels along the ear canal and causes the eardrum and the chain of tiny bones
(ossicles) to vibrate. These vibrations move through to the fluid in the cochlea, which is the part of the
inner ear shaped like a snail shell. The movement of the fluid stimulates thousands of tiny hair cells
within the cochlea which generates an electrical current in the nerve of hearing (auditory nerve). The
nerve transmits the electrical signal to the brain, and the sound is heard.
The cochlea is vitally important to the hearing process; when people have a severe or profound
hearing loss, the hair cells are usually damaged or absent and so the sound signal cannot reach the
nerve of hearing.
2 Cochlear implants
What are cochlear implants?
A cochlear implant is an electronic device that can help both adults and children who have a severe to
profound hearing loss. It is made up of two parts: an internal receiver/stimulator package and
electrode array, and the external speech processor that looks like a hearing aid. The cochlear implant
uses small electrical currents to directly stimulate the nerve of hearing, which then sends signals to the
brain where they are interpreted as sound.
University of Southampton Auditory Implant Service
Building 19, Highfield, Southampton SO17 1BJ United Kingdom
Enquiries Tel: +44 (0)23 80 59 3522 Repairs Hotline: +44 (0)23 80 58 4068
Fax: +44 (0)23 80 59 9608
Text: +44 (0)7887 790765
Email: ais@southampton.ac.uk
Website : www.southampton/ais
How does the cochlear implant work?
1. Sound from the environment enters the microphone, which is worn behind the ear like a hearing
aid
2. The speech processor selects and codes useful sounds
3. This information is sent along the lead to the transmitter coil, which attaches to the head using a
magnet
4. The coil sends the information across the skin to the receiver/stimulator
5. The receiver/stimulator converts the information into an electrical signal
6. Pulses of electricity at the electrodes stimulate the hearing nerve
7. The nerve sends a signal to the brain, which interprets the signal as a sound
Who could a cochlear implant help?
A cochlear implant can give a severely or profoundly hearing impaired person a sensation of sound. It
is suitable for people who receive limited benefit from conventional hearing aids.
What is the best age to have a cochlear implant?
A cochlear implant usually works best for adults who have become deaf after acquiring some speech,
or children who were born deaf or acquired a hearing loss. An adult who has always been deaf and
never learned to speak may not achieve good benefit from a cochlear implant.
Is the cause of deafness an important factor?
The cause of deafness is generally not important as long as the auditory nerve is able to respond to
electrical stimulation provided by the cochlear implant.
What about people with other disabilities?
Physical disability, including blindness, is no barrier to cochlear implantation, if provision is made to
ensure that the patient is able to participate in assessments and rehabilitation.
Can elderly people have cochlear implants?
If a patient is fit enough for a general anaesthetic, old age alone is not a contraindication for cochlear
implantation.
What kinds of sounds are heard with an implant?
All patients can hear and identify many environmental sounds and find that the implant helps lipreading; some individuals can understand speech without lip-reading and can even use the telephone.
Do people with a cochlear implant hear normally?
No. Patients who have lost their hearing say that sound through an implant is very different from
normal hearing. At first it is reported to be "mechanical" or electronic" sound or "like a radio that's out
of tune"; but gradually over a period of months the sound becomes clearer and more natural.
How large is the speech processor?
The speech processor is generally worn behind the ear; it is the size of a larger hearing aid.
Where does the transmitter coil go?
The coil fits behind the ear and can be hidden beneath the hair. It is held in place by a small magnet,
and is slightly larger than a 2 pence piece.
How visible is the cochlear implant system to other people?
The cochlear implant is generally only visible on patients with very short hair.
Does the speech processor use batteries?
Yes. The speech processor uses small button batteries. There is also the option to use rechargeable
batteries. These are issued free of charge.
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How long do the batteries last?
Usually a few days.
Can the processor be taken off?
Yes. The external parts of the implant can be removed at any time, for example for swimming or bed.
If the patient is not wearing the external parts, no part of the implant can be seen, but then, of course,
the patient is unable to hear.
Can someone with an implant still play sports, for example football,
swimming, tennis?
Yes. It may be necessary to remove the external parts for some sports, and protective head gear
should be worn if there is a risk of a blow to the head. Sports such as boxing, kickboxing and scuba
diving are not recommended.
What about meningitis?
There is a very slightly increased risk of contracting meningitis when you have a cochlear implant. For
this reason, the Department of Health recommends that everyone with a cochlear implant is
vaccinated against pneumococcal meningitis. This can usually be done before you receive a cochlear
implant.
Do the external parts ever break?
Yes. In common with any item that is used regularly, the processor, transmitter coil and leads. These
parts can usually be replaced immediately by the cochlear implant centre.
Do the internal parts ever break?
There have been many years of research in order to try and make the implant as reliable as possible,
but failures can occur, as with any electronic item. The manufacturers of the implant presently used in
this centre state that more than 99% of the implants were still functioning after at least four years of
use. If an implant user were to experience a failure, they would usually be offered a replacement,
which would require another operation. The re-implantation operation is quicker and more
straightforward than the initial surgery.
Does the implant user need to pay for repairs?
No. The cost of replacement equipment is funded by health authorities and therefore free of charge to
the patient. The cochlear implant can also be insured against all risks.
Why are some members of the Deaf community against cochlear
implants?
There are a small number of deaf people who do not agree with cochlear implantation, especially in
children. They are concerned that deaf culture and sign language will disappear if all deaf children
receive implants.
3 The Cochlear Implant Programme
What does the cochlear implant programme involve?
The programme consists of four main parts:
1. Assessment
2. Surgery
3. Tuning
4. Rehabilitation
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Assessment
What does the assessment consist of?
Assessment is carried out by a multidisciplinary team, including audiological scientists, ENT
consultants, specialist speech and language therapists, hearing therapists, teachers of the deaf
(children only) and radiologists.
An audiological scientist determines what the candidate can hear with and without hearing aids. If an
individual has not been using hearing aids recently or if there is a more appropriate aid, then a trial
with a hearing aid may be given over several months.
An ENT consultant sees the patient to assess if there are any medical contraindications to receiving a
cochlear implant. In addition, a detailed X-ray (CT scan) of the inner ear is performed in order to
check that an electrode can be inserted into the cochlea.
Speech and language therapists and hearing therapists also assess a candidate's suitability for
cochlear implantation, and perform a number of evaluations. Further medical, radiological and
psychological assessments may be required in some cases.
In the case of children, an educational assessment is carried out by a teacher of the deaf to provide
information and support, and to liaise with the child's school, nursery or playgroup, parents and
education service.
Is there anything else involved in evaluation for a cochlear implant?
Members of the cochlear implant team ensure that patients and their families have realistic
expectations about what the implant can do. Motivation and commitment is needed to participate in
rehabilitation following surgery. A clear understanding of the advantages and disadvantages of a
cochlear implant is essential before making the final decision.
Surgery
What happens during surgery?
The cochlear implant operation takes about 3 hours and involves the receiver/stimulator package
being placed in the bone behind the ear, and the electrodes being inserted into the cochlea. The stay
in hospital is usually only 3 or 4 days.
Are there any risks?
The surgical procedure involves entering the mastoid bone to reach the inner ear. The mastoid is part
of the skull directly behind the ear. The operation involves the same risks as other ear surgery:
infection, facial muscle weakness or paralysis and the risks of anaesthetic. These are all remote risks.
The long term risks of electrical stimulation of the auditory nerve are only partially known. However no
serious complications have arisen in any of the users implanted to date, and this procedure has been
used for over 25 years.
Other risks of cochlear implantation include a possible increase in symptoms such as tinnitus or
dizziness. Although temporary changes in these symptoms often occur following ear surgery, a
permanent increase is rare.
Can the patient hear immediately after surgery?
No. The external parts of the cochlear implant system must be used in order to hear sound. Patients
do not receive these until several weeks after surgery, when the skin is healed and the swelling is
gone.
Tuning
What is tuning?
The tuning process is the adjustment of the speech processor to suit the individual. It involves an
audiological scientist testing what the patient can hear using a special computer. Several tuning
sessions are required to reach the optimal settings.
For children receiving cochlear implants, the tuning will be incorporated into an age appropriate
listening activity; the aim is to make the sessions as enjoyable as possible.
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Rehabilitation
Once the cochlear implant is switched on, why are further
appointments needed?
The sound from the cochlear implant is very different from normal hearing, and takes a while to get
used to. Counselling and rehabilitation sessions are provided to help the patient adjust to the sound
heard through the implant and to make communication easier. The clinic staff also teach the patient
and their family how to handle and care for the external parts of the device.
During the first year a minimum of 10 visits to the implant centre are required for tuning, hearing
testing and rehabilitation. After this, patients attend less frequently although the implant centre
always keep in contact in order to provide maintenance of the device and =any further rehabilitation
required.
Children will receive regular visits from rehabilitation staff in order to provide support for parents and
local staff, monitor the child's progress and encourage the development of listening skills.
4 Experience of cochlear implant users
In this section the answers are based on the experiences of patients who have had cochlear implants;
the answers give you an idea of what to expect if you have a cochlear implant.
What kinds of sounds can be heard with the implant?
Most medium and loud sounds and some soft sounds can be heard with the implant. Patients can
learn to recognise many environmental sounds including footsteps, slamming doors, motors,
telephones ringing, dogs barking, whistling kettles, wind in the trees, the clicking of light switches.
When implant users hear these sounds, do they know what they
are?
Initially all the sounds may seem very similar. With experience and training users learn to tell
differences between sounds and over 95% of adults are able to recognise some environmental sounds
after six months of implant use.
Does the implant help lip-reading?
Yes. Implant users can hear the rhythm, pattern and intensity of speech. They say that the sound from
the implant makes lip-reading easier. The amount of help the cochlear implant provides with lipreading depends upon prior experience with sound and speech. The ability improves over time, with
experience and training.
Can implant users hear their own voices?
Yes. Many patients say the sound of their own voice is very strange at first. One lady said that her
voice sounded like Donald Duck! After several weeks however, patients report that the sound
becomes more natural.
Can the implant help people to control the loudness of their voices?
Yes. The implant allows the user to hear their own voice and background noise, and by monitoring the
background noise the implant user can control the volume of their voice.
Can people with an implant use the telephone?
Some patients can use the telephone to carry on a normal conversation, but many more can use it in a
limited way. They can hear the telephone ringing and cal tell the difference between a dial tone, a busy
signal, a ring or a voice on the phone. It may be necessary however, to use a telephone amplifier to
hear these sounds.
Implant patients can usually tell how many words or syllables the other person says; this allows them
to use a word code to give or receive a limited message. However a few users can understand some
conversation over the telephone without using a code. Telephone training is part of the rehabilitation
given.
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Does the implant help with television?
Some implant users have not found the implant particularly helpful when watching TV. Most patients
need to lip-read as well as using the implant, however TV characters are often difficult to lip-read and
competing sounds such as laughter, applause and background music also cause difficulties.
Do cochlear implant users enjoy music?
The cochlear implant system is specifically designed for speech and most cochlear implant users
describe music as a “jumble of noises”; although they can hear the rhythm, it does not sound very
pleasant. Some patients do enjoy listening to music they were familiar with before they lost their
hearing, although new music is usually not enjoyed.
Are very soft sounds heard through the implant?
The implant is designed for the user to hear normal speech sounds, from quiet to
loud voices. Very soft sounds such as a whisper, a car in the distance or footsteps on
the carpet are unlikely to be heard.
Are any sounds uncomfortably loud with the implant?
Members of the cochlear implant team make careful tests to see when the sound becomes
uncomfortable. The processor is programmed so that it will not produce sounds above the level of
discomfort. Much like normal hearing, some sounds can be startling or very loud, for example sirens
from police cars, ambulances and fire engines. The implant system has been designed so these
sounds should not be uncomfortable.
Does the implant affect head noises or tinnitus?
Some implant users have found that they have less head noise while wearing the processor. Usually
the reduction occurs only on the side with the implant. Some users have found that tinnitus is also
reduces for several hours after using the processor. Not all users have a reduction in head noise,
some have noticed no change at all, others have commented that it has increased.
How long is it before maximum benefit is obtained from the
cochlear implant?
Learning the best ways to use this type of sound is a continuous process. For adults big improvements
are made in the first year, but they often report that their performance continues to improve even after
several years of implant use.
For children who have little or no prior experience of sound, the process is slower and it may be
several years before big improvements occur.
Can implant users tell the direction that sound is coming from?
Not usually.
5 Cochlear implants in children
The following questions relate specifically to cochlear implants in children
At what age do children receive a cochlear implant?
When a child has gone through the assessment process and the decision has been made that they
would benefit from an implant, it is usually advantageous for the operation to be performed as soon as
possible. The average age at implant for this centre is 3 years, although some children have been
implanted at 2 years or less.
Do some children benefit more than others from the implant?
There are many factors which will influence a child’s progress with a cochlear implant. These include
the age when the child became deaf, the length of deafness before surgery, communication methods,
experience with hearing aids, condition of the cochlea and auditory nerve and the motivation of the
child and family. Generally those children who have been deaf for a shorter period of time have a
better outcome that those who have been deaf longer.
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Can children who are born deaf have a cochlear implant?
Yes. Many children who receive cochlear implants were born deaf or lost their hearing at a very early
age. However if a child has no memory of sound it is important that the implant operation is performed
in the first few years of life, as this is when the pathways in the brain relating to sound are formed. As a
child who is born deaf grows older, the benefit they will receive from the implant decreases.
Does the cochlear implant affect a child’s behaviour?
Parents and teachers often report a decrease in behaviour problems as the cochlear implant eases
communication difficulties. Some children may be more attentive and interact better with their peers.
Will intensive therapy be needed?
Having a cochlear implant can be a strange experience to a young child; they will need a lot of support
to learn to make use of the new auditory information. All children receive regular visits and support
from the implant centre rehabilitation staff and will also have a lot of help from their local staff.
Should my child learn sign language?
It is very important that a child has some method of communication during the early years of life, so
some parents do use sign language or gesture to interact with their child. If a child receives a cochlear
implant, they have the potential to learn to understand speech and even speak themselves, so it is
important that they are given full access to spoken language. However many children will continue to
use sign language to support their communication.
What type of school should a child with an implant attend?
Children with cochlear implants can be found in a wide variety of educational settings; mainstream,
hearing impaired units and schools for the deaf. The implanted child needs to have access to speech
in order to obtain the maximum benefit from their implant.
Can a cochlear implant be used with a radio aid?
Yes.
6 Research aspects
When did cochlear implantation begin?
Experimentation with electrical stimulation of the ear was first performed by French researchers in the
late 1950s. Since the, investigators around the world have been developing this treatment; the first
adults were implanted in Southampton in 1990, and the first children in 1992.
What is the longest time that someone has had an implant for?
One patient has worn an implant continually since 1973.
Is it dangerous to have electricity so close to the brain?
All implant patients have been closely monitored and will continue to be so. No ill effects have been
reported to date.
The cochlear implant is a fairly new device. Is any further research
being done?
Yes. A large amount of research is being done both here and abroad. Researcher aim to improve the
quality of sound by developing new speech processing strategies, and they constantly aim to make the
devices more reliable. As with hearing aids, the aim is to miniaturise the cochlear implant system as
much as possible, in order to improve cosmetic aspects.
Can an implant user contribute to research?
Yes. Naturally it is the implant users who provide the information about what they can hear. Everyone
who has an implant contributes to research by participating in testing. Reports and journals written by
implant patients are also a valuable source of information.
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Can people with implants benefit from future improvements that
occur?
Yes. Improvements in the speech processing strategies usually involve changing just the external
components.
Should I be implanted now or wait for improvements in the
technology?
Improvements have and will continue to occur in implant technology. The evidence indicated however,
that shorter periods of time between onset of deafness and use of implant produce better results.
Current users have taken advantage of improvements in the external device, however to change the
implanted receiver/stimulator requires surgery again.
We hope this booklet has answered some of your questions. Please feel free to contact us for further
information.
All enquiries to: University of Southampton Auditory Implant Service, Building 19, University of
Southampton, Highfield, Southampton, SO17 1BJ.
Telephone and Minicom: 023 8059 3522,
Fax: 023 8059 9608,
Email: ais@southampton.ac.uk
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