Cochlear implants

Cochlear implants are surgically implanted devices, with an external processor, that give a sensation of hearing by using electrical signals to stimulate the auditory nerve.
They may be suitable for children and young people with severe to profound permanent deafness who don't benefit from hearing aids.
Who can use cochlear implants
Cochlear implants are usually suitable for children and young people with severe to profound permanent deafness who do not benefit from hearing aids.
It’s common for children to be implanted before they are 12 months old as research shows they will get the most benefit the younger they’re implanted. However, it takes time to find out the exact level of a child’s hearing loss and to assess their suitability for a cochlear implant, so some children may be implanted later.
Older children can also benefit from cochlear implants, including those who lose their hearing after learning to speak (for example, following meningitis). Children with progressive deafness (deafness which gets more severe over time) may become eligible for cochlear implants later. Many older children and young people adapt well to cochlear implants and learn to use them effectively.
How cochlear implants work

A cochlear implant has three main parts:
- External part: This hooks over the ear, similar to a hearing aid. It includes the microphone and sound processor.
- External transmitter coil: This is attached to the sound processor by a cable. It is held in place on the side of the head behind the ear by magnetic attraction to the implanted receiver.
- Internal receiver: This is surgically implanted under the skin behind the ear.
Some newer models, such as the Cochlear Kanso 2, combine the microphone and sound processor with the external transmitter coil. The means the whole unit is attached to the head using a magnet, removing the need for a separate part that hooks over the ear.
A cochlear implant works in these steps:
- The microphone picks up sounds.
- The sound processor converts these sounds into a digital code.
- The digital code is sent to the transmitter coil, which passes it through the skin to the internal receiver.
- The internal receiver converts the code into an electrical signal.
- The electrical signal travels along a wire to electrodes in the cochlea.
- The electrodes stimulate the cochlear nerve fibers, which send the signal to the brain.
- The brain processes these signals so the wearer can understand the sounds.

Getting cochlear implants
Before a child or young person can get cochlear implants, they need to be assessed by a cochlear implant team. If appropriate, an audiologist will refer a child to a cochlear implant centre for assessment.
Cochlear implants are available free of charge through the NHS if a child meets the criteria.
Find out more about the referral and assessment process.
How sound is perceived
The brain perceives sound through a cochlear implant differently from natural hearing, and while cochlear implants help children hear more clearly, they do not restore typical hearing.
Cochlear implant wearers who have heard naturally before often describe the sound as robotic or tinny. However, over time, the brain adjusts to the new signals and what it hears becomes more natural sounding.
We cannot know exactly what someone with cochlear implants hears as it can vary from person to person. However, there are some simulations that can give us an idea, such as this cochlear implant simulation from the University of Southampton Auditory Implant Service.
Making a decision about cochlear implants
Deciding to get cochlear implants is a life-long commitment. For some families and young people, this can be a difficult decision as there are many things to consider.
What to consider when making a decision.
Connecting with other technology
Most modern cochlear implants have Bluetooth and can connect wirelessly to phones, computers, alerting systems, radio aids and more.
Some cochlear implants also connect to compatible technology using a streamer or other device. Find out more about assistive technology.
Additionally, some modern cochlear implants are compatible with a smartphone app, which you can use to track the sound processors using GPS. This can be especially useful if your child has a habit of removing their processors while out and about, as you can then use the app to find them. The cochlear implant service will tell you if your child’s cochlear implants connect to an app and can help you download the app to your smartphone.
For advice about your specific device and its compatibility with other technology, you can ask your implant centre or contact our Helpline.
You can also use Connevans' online tool to explore compatible assistive technology and accessories for different cochlear implant brands.
Check out our free children's comic
Chloe decides with her family to get cochlear implants and learns all about them on their journey.
Full references for this webpage are available by emailing
informationteam@ndcs.org.uk