Cochlea, Cochlear Implant
The cochlea is the part of the inner ear that converts vibrations into nerve impulses sent to the brain. It is the organ of hearing. The cochlea is a small conical structure resembling a snail shell. The word “cochlea” is a Latin word derived from the Greek kokhlos meaning land snail. The cochlea winds two and three quarters turns about a central bony axis, forming the front part of the labyrinth (a maze within the inner ear). The cochlea contains the Organ of Corti which is the receptor for hearing.
A cochlear implant is a small complex electronic device that is surgically implanted within the inner ear to help persons with certain types of deafness to hear. Cochlear implants rarely cure severe or profound deafness but they can help some hearing-impaired people to distinguish the sounds of language clearly enough to participate in conversation. For children who are born deaf, a cochlear implant can markedly increase the child’s chance of being able to function effectively in school. A cochlear implant has four basic parts: a microphone, which picks up sound from the environment; a speech processor, which selects and arranges sounds picked up by the microphone;a transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses; and electrodes, which collect the impulses from the stimulator and send them to the brain. Whereas hearing aids amplify sound, cochlear implants compensate for damaged or non-working parts of the inner ear. A cochlear implant electronically finds useful sounds and then sends them to the brain. Deaf children who receive cochlear implants in infancy tend to have neurological development closest to that of hearing children. Adults who have lost all or most of their hearing later in life may also benefit from cochlear implants. Older candidates can often associate the sounds made through an implant with sounds they remember. This may help them to understand speech without visual cues or systems such as lipreading or sign language.