A cochlear implant is a device that allows the deaf or extremely hard of hearing to hear again. About 100,000 people worldwide have these implants. A cochlear implant works by bypassing the eardrum and directly stimulating the cochlea, the spiral-shaped structure in our inner ear responsible for detecting sound.
A small microphone implanted just above the ear connects to a speech processor, which filters speech from surrounding noise, which uses electromagnetic induction — the same phenomenon exploited by metal detectors and RFID tags — to send a signal to a receiver and stimulator located in the inner ear, which sends auditory signals directly to the brain.
The total cost of a cochlear implant, including surgery and post-implantation therapy, runs between $45,000 and $55,000 US Dollars (USD), but can be as high as $80,000 USD for adults born deaf who require additional therapy to learn to process sounds. About 3,000 people have bilateral implants, that is, one in each ear, and this trend is growing, with about 15% of cochlear implantees in the United States choosing this option today. Cochlear implants were invented back in the 1970s.
Cochlear implants may come with different types of software for the speech processing module, which emphasize different parts of sound. This software is continuously improving and in many cases new versions can be added in to preexisting patients without the need for additional surgery. Cochlear implants are most successful with children, who, even if born deaf, have the necessary neural plasticity to pick up the faculty of hearing with the least training. The longer you have been deaf, the more intensive the post-surgery training needs to be. Because the implantation of a cochlear implant destroys prior hearing capabilities in the ear in which it is implanted, this therapy is only recommended for those who are already entirely deaf or near-deaf.
Cochlear implants have sparked intense ethical debates among the medical and deaf communities. Some deaf people feel that cochlear implants unnecessarily alienate deaf people from the deaf community, particularly in situations where deafness runs in the family. But children receiving the implants give overwhelmingly positive feedback, and rarely if ever regret their parents' decision to go forward with the implant.