Rehabilitation of hearing impaired patients with cochlear implants - an overview

The aim of this paper is to provide an overview of the cochlear implant. Th e history of this entity is traced from the early development of implants, involving the stimulation of the hearing nerve, up to the currently availab le standard multichannel implants. The physiological background is also elu cidated. A cochlear implant consists of an implantable portion which lies within the ear, and of parts that are worn externally on the body. Differences betwee n the first implants and those now in use are as follows: transcutaneous in formation and energy transmission, the position of the electrode in the ear , and the configuration of the electrode. Differences between the currently available implants mainly concern the number of electrodes, speech coding strategies and the mode of electrode stimulation. Almost all of the most re cent implants are equipped with electrodes that are implanted in the tympan ic scale of the cochlea.