A cochlear implant is a small device that provides direct electrical stimulation to the auditory (hearing) nerve in the inner ear. It was developed to help children and adults with a severe to profound hearing loss who cannot be helped with hearing aids may be helped with cochlear implants.
This type of hearing loss is called ‘sensorineural,’ which means there is damage to the tiny hair cells in the part of the inner ear called the cochlea. Because of this damage, sound cannot reach the auditory nerve. With a cochlear implant, the damaged hair cells are bypassed, and the auditory nerve is stimulated directly.
The cochlear implant does not result in “restored” or “cured” hearing. It does, however, allow for the perception of the sensation of sound.
The benefits from a cochlear implant depend on many factors, such as:
· The age of the patient when he or she receives the implant
· Whether the hearing loss was present before or after the patient developed language skills
· The motivation of the patient and his or her family
Cochlear implants have external (outside) parts and internal (surgically implanted) parts that work together to allow the user to perceive sound.
The external parts include a microphone, a speech processor, and a transmitter. The microphone looks like a behind-the-ear hearing aid. It picks up sounds—just like a hearing aid microphone does—and sends them to the speech processor.
The speech processor may be housed with the microphone behind the ear, or it may be a small box-like unit typically worn in a chest pocket. The speech processor is a computer that analyzes and digitizes the sound signals and sends them to a transmitter worn on the head just behind the ear. The transmitter sends the coded signals to an implanted receiver just under the skin.
The internal (implanted) parts include a receiver and electrodes. The receiver is just under the skin behind the ear. The receiver takes the coded electrical signals from the