Why do people need cochlear implants?
In some people, the hair cells inside the cochlea become damaged, either before birth or later on in life. This is called ‘sensori-neural deafness’. In this condition, although sound travels through the ear in the usual manner, the hair cells are not stimulated and so no nerve impulse is sent to the brain. The hair cells can be damaged to such an extent that no sound is heard, or, in some cases, only loud volume noises can be heard. Some people can be fitted with hearing aids, which amplify (make louder) sounds until they can be picked up by the hair cells. However, this will not benefit people whose hair cells are too damaged to pick up any sound and in these cases a cochlear implant may be suggested.
