A coclear implant is an electronic device designed to provide sound information for adults and children who have a profound sensironeural hearing loss (nerve deafness) in both ears and show no ability to understand speech through hearing aids.
The first research on cochlear implants was conducted in France 30 years ago. Since then, cochlear implant technology has evolved from a device with a single electrode or channel to systems that transmit more sound information through multiple electrodes or channels.
taken from:
Cochlear Implants FAQ