Chapter One
Implant design and Development

David B. Grayden and Graeme M. Clark

Introduction
The cochlear implant is an electronic device that is implanted under the skin with electrodes positioned in the cochlea to stimulate the auditory nerve. Electrical currents induce action potentials in the auditory nerve fibres and these are transmitted to the brain. It thus bypasses damaged or missing hair cells within the cochlea that would normally code sound. It consists of a receiver stimulator, which receives power and decodes instructions for controlling the electrical stimulation, and an electrode array, which has electrodes placed near the auditory nerve (generally in the cochlea) to stimulate residual auditory nerve fibres.
In addition, there is an external component (speech processor) that contains a microphone and device for picking up and processing incoming sound to create a ... read full excerpt from Cochlear Implants: A Practical Guide ebook