What is a cochlear implant?
We are not going to go into great depth here. There are many detailed descriptions and a wealth of information available on the internet, so we are just giving you a brief, non-technical outline.
A cochlear implant is a surgically implanted device suitable for severely/profoundly deaf children and adults who do not derive sufficient benefit from hearing aids. For these individuals cochlear implants are by far the best that technology can do to reduce the adverse impact of deafness at the present time.
The device consists of two parts:
- The external part: a battery powered sound processor (1) with a microphone (2) and, on the side of the head behind the ear, a transmitter coil (3) which is attached magnetically (4) to……
- the internal part (not visible externally): a receiver (5) surgically implanted in the mastoid bone behind the ear; attached to it is an electrode array (6) that is inserted into the cochlea (7).
There are various types of electrode arrays to suit different cochleas.
The microphone on the sound processor picks up the sound, which is converted into an electrical signal. This is then coded and sent via the transmitter coil to the receiver by radio waves. The receiver converts this into electrical signals which are transmitted along the electrode array. The electrodes inside the cochlea stimulate the cells at the end of the hearing nerve (8) over different frequencies, and this nerve transmits signals to the hearing centre of the brain which interprets them as sound.
Following referral to a cochlear implant centre, a thorough assessment will take place to determine a child’s suitability for the procedure. In the past children were only offered one cochlear implant. However, nowadays unless one ear has good residual hearing or there is a medical reason to only implant one ear, children are routinely offered bilateral cochlear implantation. This has been the case since the National Institute for Health and Clinical Evidence (NICE) issued their Technology Appraisal Guidance 166 on 28th January, 2009, recommending simultaneous bilateral cochlear implants for deaf children meeting the audiological criteria. It also entitled children who already had a unilateral cochlear implant at that date to have the option of a sequential bilateral implant if the responsible clinician considered it would provide sufficient benefit, and you can read about the outcomes for several such children in this booklet.
Surgery may require an overnight stay in hospital although in many cases the procedure is now performed as a day case. Around four weeks later the device will be ‘switched on’ and the child’s journey into the world of sound begins. There will then be ongoing routine visits to the implant centre to programme the device and monitor the child’s progress. Models of rehabilitation vary from centre to centre. For example, for the first year some may ask the child to visit the centre for regular therapy, some may offer Auditory Verbal Therapy for a fixed period, others may have a teacher of the deaf and/or speech and language therapist who visit the child at home and school over a longer period and work with the family and local team to deliver support.
Note: There are other implantable devices for different types of deafness which are not covered on our site: (a) bone anchored hearing devices (for conductive hearing loss, mixed hearing loss or single-sided deafness) use bone conduction to transfer sound to the inner ear; (b) middle ear implants (for mild to severe sensorineural, conductive or mixed hearing loss) if conventional hearing aids cannot be worn, eg because of chronic ear infections; (c) electro-acoustic implants (for mild to moderate hearing loss in the low frequencies and severe to profound loss in the high frequencies) combine cochlear implant and hearing aid technology in one device. The hearing aid component amplifies the low pitches and the cochlear implant provides stimulation for higher pitches; (d) auditory brainstem implants can be used in exceptional cases of profound hearing loss when a cochlear implant cannot be used, for instance if there is no cochlea or auditory (hearing) nerve. We suggest using the internet for further information about these devices.
Bilateral cochlear implantation
Nowadays the vast majority of severe to profoundly deaf children are offered bilateral cochlear implants (one implant in each ear), but this has not always been the case. In January, 2009 NICE published the following guidance which led to the availability of bilateral implants:
Cochlear implants for children and adults with severe to profound deafness (published January, 2009)
The CICS Group was proud to be appointed as a consultee to the NICE Technical Appraisal of cochlear implants, and the Trustees are delighted that the evidence that CICS provided contributed to NICE’s decision to recommend (as an option for people with severe to profound deafness who do not receive adequate benefit from acoustic hearing aids) unilateral implantation for all adults, simultaneous bilateral cochlear implantation for children and sequential bilateral implantation for children who already had one cochlear implant at the date of the announcement of the Guidance.
National Paediatric Bilateral Audit
http://www.bilateralcochlearimplants.co.uk/ (Ben can you set up another link to the actual leaflet attached to the email from Devyanne of 3rd Sept?)
Fourteen cochlear implant centres in the UK formed a consortium and agreed on appropriate test procedures to audit the benefit children receive from bilateral cochlear implants. The consortium took advice from specialist researchers, clinicians, surgeons, and a representative from a patient group (CICS Group)
Data collection occurred at four intervals: before bilateral cochlear implants or before the sequential implant, one year, two years, and three years after bilateral implants. The measures evaluated localisation, speech recognition in quiet and background noise, speech production, listening, vocabulary, parental perception, quality of life, and surgical data including complications.
The above link will take you to the details of the audit.
A leaflet summarising the outcome is available at (Ben – awaiting this link)
Or a paper copy can be obtained from the CICS Group Click here to send a request for a copy (Ben can you set up such a link please)
2ears2hear is a website for everyone with an interest in bilateral cochlear implants and the importance of securing NHS funding.
The site has not been updated for several years but is still a useful source of background, information and case studies.
Cochlear implantation – multi-professional group
British Cochlear Implant Group www.bcig.org.uk
A professional body representing the multi-professional groups working in auditory implant centres throughout the UK. Publishes quality standards documents and recommended guidelines on safety for CI users.
Paediatric Auditory Implant Centres
Kilmarnock – The Scottish Cochlear Implant Programme for Adults & Children
All three manufacturers have comprehensive websites which are regularly updated with details of their latest devices, developments and innovations:
The HiResolution Bionic Ear System is the only cochlear implant system that can provide HiResolution sound to children and adults with severe or profound hearing loss. HiResolution sound is designed for the REAL WORLD, where every detail of sound matters.
Cochlear is the leader in cochlear implants supporting over 200,000 Nucleus recipients across the world. Cochlear continues to lead the way in innovation, participating in more than 90 collaborative research programs with university and research hospitals in more than 35 countries.
MED-EL cochlear implant systems combine the latest expertise in technology and hearing science for unparalleled performance, safety and reliability. The MAESTRO® cochlear implant system comprises of two speech processors, different wearing options, two implant designs and a wide variety of electrode arrays.
CI User groups/internet circles
The European Association of Cochlear Implant Users represents on a European level the interests of deaf or hearing impaired people who have regained hearing perceptions through a cochlear implant.
Established and run by adult CI users HCCIG is a support network where implantees, potential implantees and parents of children with cochlear implants can exchange information and discuss all aspects of cochlear implants in a social environment.
The NCIUA was established to provide practical support to implant users, their family and friends. It encourages best practice in the provision of cochlear implants, rehabilitation, aftercare and appropriate educational opportunities for children.
Internet forums (internet circles on existing website)
There are too many internet forums and Facebook groups to list here, but here are a few examples of useful sources of information on deafness and cochlear implants.
CI Circle – US
Send an e-mail to: firstname.lastname@example.org. In the body of the email type: subscribe cicircle
No 9 Parent Place (NDCS)
www.ndcs.org.uk and then click on the appropriate link. Topics cover all aspects of parenting a deaf child, not just cochlear implantation.
A website, with a forum, information and resources for CI users, their parents and professionals working with children and teenagers with cochlear implants.
Info for teens
A fun website for teenagers who are interested in cochlear implants. Case studies are out of date but site is useful for age appropriate basic information.
A site closely monitored by NDCS, The Buzz gives deaf young people the opportunity to make friends, check out the latest information and to chat and discuss issues that matter to them. There are two sections: age 8 – 11 and age 12 – 18.
A section within The Ear Foundation’s Sounding Board called which is for teenagers to access information about cochlear implants and the issues around using them. It contains tips from teenagers and profiles from teenagers and young adults, describing their different journeys.