If you're very hard of hearing or deaf, a cochlear implant may help you get back a sense of sound. It isn't a hearing aid, which makes sounds louder. It’s a small device that a doctor puts in your ear through surgery. It works by sending impulses directly to your auditory nerve, which carries sound signals to your brain.
Although a cochlear implant doesn't make you hear normally again, it can help you with sounds. Most people with severe to profound hearing loss can understand speech in person or over the phone better than they did with a hearing aid. It can usually help you recognize sounds around you, including telephones, doorbells, and alarms. Many people also can pick up on speech in noisy environments better than they did with hearing aids, or even enjoy music again.
How does a cochlear implant work?
Cochlear implants are designed for children and adults with sensorineural hearing loss. This type of hearing loss typically involves damage to tiny hair cells in a part of your inner ear called the cochlea. These hair cells usually pick up the vibrations of sounds and send them to the brain through the auditory nerve. When they’re damaged, sound can't reach that nerve. A cochlear implant skips the damaged hair cells and sends signals to the auditory nerve directly.
The devices have two parts: one part, the receiver-stimulator, is placed under your skin through surgery, and the other, the speech processor, is worn behind your ear like a hearing aid. The outside part is slightly larger than a normal behind-the-ear hearing aid.
First, a surgeon puts a receiver under your skin behind your ear through a small cut. The receiver is connected to electrodes, which she’ll put into a part of your inner ear called the cochlea. The surgery takes 1-2 hours, and you’ll probably go home the same day.
One to 2 weeks after surgery, your doctor will fit your speech processor. You wear a microphone, which looks like a hearing aid, behind your ear. The processor may be connected to the microphone and worn at your ear, or you might wear it somewhere else on your body, depending on how active you are, your age, or your lifestyle. These processors offer different programs and telephone options. They also can connect to assistive listening devices and other technology you use, like an iPod. Some have rechargeable batteries, which can lower costs over time.
When there are sounds around you, the microphone and processor pick them up and change them into electrical impulses. Then the transmitter sends these coded signals to the receiver under your skin. Next, the receiver delivers the signals to the electrodes inside your cochlea. These electrodes stimulate the auditory nerve, which carries the signals to the brain, where you recognize them as sound.