It is a surgically implanted device, which provides a hearing sensation to the patients who have severe to profound deafness and who gets either no or little benefit from hearing aid.It bypasses the damaged part (hair cells) of the inner ear and sends electrical stimulation to the nerve ganglions and the hearing nerve, which is then interpreted as sound, by the brain. To know more visit here: http://entspecialistindelhi.com/cochlear-implantation.php