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How a Cochlear Implant Works

How a Cochlear Implant Works

A cochlear implant sends an electrical message through a wire called an electrode directly to the auditory nerve, bypassing the damaged or absent hair cells. This means that, provided that the auditory nerve is still working, profoundly deaf people can hear sound. The cochlear implant consists of two parts, a surgically implanted internal part and an externally worn part called a processor.


Is a Cochlear Implant better than a hearing aid?

That depends on your hearing loss! Hearing aids work by making ordinary sound louder (‘amplification'). This may be all that is needed for people with mild or moderate-severe hearing losses. However, for people with more severe or profound losses, making the sounds louder may not help, because the damaged or absent hair cells cannot pick them up.  For these people, a cochlear implant (which bypasses the hair cells and sends an electrical signal directly to the auditory nerve) may be more effective.

Might I or my child benefit from an implant?

A detailed assessment is needed to find out whether someone is likely to benefit from a cochlear implant. The assessments are carried out by the cochlear implant team.   As a general guideline, to be considered for an implant you need to meet the following criteria:

  • Severe to profound sensori-neural hearing loss in one or both ears
  • Receive only marginal benefit from hearing aids
  • Medically suitable for surgery
  • Strongly motivated for the (re)habilitation process
  • Having a good support network from family, friends, or other professionals

The implant team assesses each case individually and will look at these issues and at any other pertinent factor which will affect whether or not you or your child are likely to benefit from a cochlear implant.

Can children born deaf benefit?

Children, who are implanted when very young, ideally before they reach four years old, usually do very well with their implants.   Children implanted over 5-7 years of age who were born profoundly deaf and have been unable to make good use of hearing aids are less likely to receive significant benefit.  This is because the brain learns to interpret sound most effectively in the first few years of life. However, older children and adults, who have made good use of hearing aids and have spoken language skills, may be able to benefit from an implant.

What about children who have gone deaf?

Children who were born hearing, or with minor hearing losses, but whose hearing has deteriorated to severe or profound can do well with a cochlear implant.   The sooner they receive their cochlear implant after the onset of deafness, the better they are likely to do. Cochlear implants have been helpful for thousands of children worldwide who have lost their hearing for different reasons, including meningitis.

Can adults benefit?

Adults who have lost their hearing can greatly benefit from a cochlear implant.  As for children, the sooner they receive their implant after a severe to profound sensori-neural hearing loss is diagnosed, the more benefit they are likely to receive from the cochlear implant. 

Adults who have been deaf since early childhood and  have limited or no memory of sound and speech are unlikely to receive much benefit from a cochlear implant.