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Cochlear Implants (CI)

A Cochlear Implant is a device which can provide access to sound and the sensation of hearing to people who have permanent, severe to profound deafness.

These people typically do not hear the full range of speech sounds with standard hearing aids.

For more information on hearing, types of hearing losses and hearing solutions, visit:

How they work

A Cochlear Implant is different from a hearing aid. It is an electronic device comprising two components:

  • an internal part - known as the electrode implant - which is inserted into the ear during surgery
  • an external part - known as a processor - which is worn on the head, behind the ear or clipped to clothing.

A Cochlear Implant turns sound into electrical signals. Instead of simply making sounds louder, like a conventional hearing aid would, the Cochlear Implant provides a sensation of hearing by directly stimulating the auditory nerve using electrical signals.

With a Cochlear Implant, the sound is picked up by the microphone worn on or near the ear on the external processor.

CI external processor device

The sounds are then processed, changed into electrical signals, and passed to a transmitter coil worn on the head and kept in place via a magnet.

Small boy with cochlear implant device on his head sits in nursery classroom smiling at laughing young woman playing guitar

© Cochlear Limited 2023. Image courtesy of Cochlear Limited.

The signals are sent by radio waves, through the skin to the implanted receiver and down the wire to the electrode in the cochlea. When the electrode receives the signal, it makes tiny currents that travel along the auditory nerve to provide a sensation of hearing.

Cochlear implantation can greatly improve quality of life by providing better access to sound, however, it is important to note that the signal received from the implant is not the same as normal hearing.

People who receive cochlear implants require time and training to become accustomed to the new sound.


How Cochlear Implants Work - Cochlear Americas (YouTube)

Who is suitable

A Cochlear Implant is suitable for people with a severe to profound sensorineural hearing loss, who have reached the limits of what a conventional hearing aid can do.

Cochlear Implants are generally most successful for people who have had a relatively short length of deafness. So, children who are born deaf, or are deafened at a young age, benefit from cochlear implantation as early as possible, once they are big enough to have the surgery.

Adults who have become deaf, or whose hearing has worsened to a point where hearing aids are no longer beneficial, also generally do better with a Cochlear Implant.

Adults and children who have been deaf for many years, and who have very little auditory experience (i.e. have not consistently worn hearing aids) tend to take longer to habilitate, and are less likely to hear as well, with a Cochlear Implant as those with a short duration of deafness.

This is because the auditory pathways in the brain become fixed as 'non hearing' pathways, and it is difficult for the brain to adapt to hearing and make use of sound in a meaningful way.

Cochlear Implants can still benefit this group of people, but they need to be aware that the outcomes will be variable.

Oxford Auditory Implant Programme accepts referrals for children and adults of all ages who are unable or unlikely to benefit from hearing aids and who are eligible for NHS care.

We are always happy to discuss whether a Cochlear Implant is likely to be suitable for you, or someone you know.

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Last reviewed:22 September 2023