HOW DOES A TRADITIONAL COCHLEAR IMPLANT WORK?

Cochlear implants are small hearing devices fitted under the skin behind the ear during surgery.

They have an external sound processor and internal parts, including a receiver coil, an electronics package and a long wire with electrodes on it (an electrode array).

The external processor takes in sound, analyses it and then converts it to signals that are transmitted across the skin to an internal receiver-stimulator, which sends the signals along the electrode array into a part of the inner ear called the cochlea. 

The signal is then sent to the brain along the hearing nerve as normal. 

This means cochlear implants are only suitable for people whose hearing nerves are functioning normally.

The implants cannot restore normal hearing but they can give a deaf person a good representation of sounds, helping them understand speech.

Whereas hearing aids amplify sound so they can be detected by damaged ears, cochlear implants bypass damaged parts of the ear and directly stimulate the auditory nerve.

Signals generated by the implant are sent via the auditory nerve to the brain, which recognizes the signals as sound.

Hearing through an implant is different from normal hearing and takes time to get used to it.

It allows people to recognize warning signals, understand their environment and enjoy conversations with people. 

If a cochlear implant is recommended, it will be inserted into the ear (or both ears) during an operation and switched on a few weeks later. 

Source: NHS Choices