What is a Cochlear Implant ?

How do cochlear implants work?

A cochlear implant (Bionic Ear) is an artificial hearing device, designed to produce useful hearing sensations by electrically stimulating nerves inside the inner ear. The Bionic Ear pioneered in 1978 by Professor Graeme Clark and his team.

The present day multi-channel cochlear implants, consist of 2 main components: 1) the cochlear implant package and electrode array (or receiver-stimulator) and 2) the speech processor and headset. The model shown in the Figures below is the Cochlear Ltd. Nucleus® 24 cochlear implant system, which was released in 1997.

 

All of the parts shown in Figure 1. are placed under the patient's skin behind the ear during the implant operation. The implant package (or receiver-stimulator) contains the circuits that send electrical pulses into the ear. Attached to the package are tiny wires that join to electrodes. The implant package also contains an antenna that receives radio-frequency signal from the external coil.

The 22-electrode array is inserted into the shell-like structure in the inner ear known as the cochlea. The ball electrode is placed under a muscle near the ear. There is also a plate electrode on the outside of the receiver stimulator package..

The other parts of the implant system are worn externally. There are no plugs or wires connecting the internal and external components. The coil is held in position against the skin by a magnet and the microphone is worn behind the ear. The body-worn speech processor (SPrint™) can be worn in a pocket, in a belt pouch or in a harness. The ear-level processor (ESPrit™) is worn behind the ear. These parts, which are shown in Figure 2. are normally fitted two weeks after the operation.

How do cochlear implants work?

  Date Created: Thursday February 19 2004
  Last Updated:  Tuesday July 29 2008
  Authorised By: Director, Audiological Services
  Maintainer: Webmaster, The Bionic Ear Institute
  Email: webmaster@bionicear.org
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