CochlearImplant

A cochlear implant is a medical device that provides a sense of sound to people with severe to profound sensorineural hearing loss when conventional amplification does not offer sufficient benefit. Unlike a hearing aid, it bypasses damaged hair cells and stimulates the auditory nerve directly.

The system comprises an external speech processor, a microphone, and a transmitter; a surgically implanted internal receiver and stimulator, and an electrode array inserted into the cochlea. Sound is captured, processed, and conveyed as electrical impulses to the auditory nerve.

After implantation, a recovery period precedes fitting the external processor. Audiologists perform mapping sessions to set stimulation levels and adjustments. Rehabilitation programs help users learn to interpret electrical sound. Some users also use a hearing aid in the opposite ear (bimodal hearing).

Candidacy includes children and adults with severe to profound hearing loss who receive limited or no benefit from hearing aids, with appropriate medical clearance. Early implantation in children is associated with better language outcomes. Imaging and medical evaluation assess anatomy and health risks.

Surgical risks include anesthesia complications, infection, and device malfunction. There is a small risk of meningitis, tinnitus, and balance disturbances. Cochlear implants do not restore normal hearing and outcomes vary with age of implantation, duration of deafness, and rehabilitation.

Most users gain improved speech awareness and some speech understanding, particularly with training. The device requires ongoing maintenance, occasional replacements for external components, and periodic reprogramming, with many users continuing use for decades.