A medical device that is used to help alleviate a hearing impairment. The cochlea is the part of the inner ear that actually helps with hearing. Inside it is the basillar membrane, which consists of a bunch of hairs that vibrate depending on the vibrations of the eardrum which is connected to the cochlea via a group of small bones called ossicles, all curled up in a spiral. With a cochlear implant, they put a complicated segmented wire through the cochlea, and then using electric currents, make the basillae vibrate. There are usually something like 15 segments on the wire, each of which can be activated to stimulate different basillae, leading to the perception of different frequencies.

Despite what people say, they do not make hearing that much easier. If you actually listen to simulations of what people with cochlear implants are hearing, it's like someone whispering breathily. They are very sensitive to background noise, and stuff up particularly on music.

Furthermore, it's a great solution for those who are post-lingually deaf; but doesn't work that well for people who were born deaf, or are pre-lingually deaf.

The reaction from the Deaf community (as compared with those who are just deaf, but don't identify with the Deaf community) has been mixed; mainly because they feel it doesn't solve the problem. What point is hearing if you've never learnt a hearing language, and the modality you've used since childhood for language has been visual? The brain is plastic, meaning that even if deaf people can be made to hear later in life, then it's very difficult for them to learn language.