What is a cochlear implant?
Cochlear implants provide a sensation of hearing to those who have severe to profound deafness. This means that they may be able to hear some sounds, but not all that make up human speech.
Instead of making the sound louder, like a hearing aid, implants use electrical signals to directly stimulate the auditory nerve (the nerve that carries sound from the cochlea to the brain).
The idea is to provide access to the range of sounds that make up speech. Results vary depending on the individual, and range from an awareness of environmental sounds to hearing speech.
How do cochlear implants work?
Cochlear implant have several different parts, some of which are internal (cannot be seen) and some of which are external (worn on the body).
- The internal part consists of a receiver with a magnet that is fitted under the skin behind the ear, plus electrodes inserted into the cochlea.
- The external part consists of a microphone and sound processor with a transmitter coil.
Sound is picked up by the microphone in the cochlear implant and processed into electrical signals that are passed to the transmitter coil.
The transmitter coil sends signals, by radio wave, through the skin to the implanted receiver. The receiver sends the signals down the wire to the electrodes in the cochlea. When the electrodes receive the signal, a tiny electric current stimulates the auditory nerve to provide a sensation of hearing.
Who can benefit from cochlear implants?
If you have severe to profound deafness and want to find out whether a cochlear implant could help you, your GP, audiologist (hearing specialist), or your ear, nose and throat (ENT) specialist can refer you to a cochlear implant centre for an assessment. To find out more, see our factsheet cochlear implants.
How is Action on Hearing Loss helping research?
We are funding research to improve the technology for cochlear implants and to make sure more people benefit from them.
The research focuses on:
- demonstrating the benefits of cochlear implants
- refining the methods used to determine whether someone is suitable for an implant
- finding ways to improve how cochlear implant users hear speech, especially in noisy environments
- developing rehabilitation tools, such as training programmes, to help people learn to interpret the sounds they hear through the implant.
To find out more about the research we fund, visit our biomedical research section.