Audiology
Cochlear Implant
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What is a cochlear implant?

A cochlear implant (Cl) is a small device that helps improve your hearing. Normally, sounds are changed into electric signals by special hair cells in your cochlea. The signals are sent through your auditory (hearing) nerve to your brain, allowing you to hear sound. The cochlea is inside your inner ear and is the main body organ for hearing. Damage to the hair cells causes hearing loss. You may need a Cl if you are very hard of hearing and hearing aids do not help. Your doctor may also decide that you should have a Cl if you are deaf.

How does a cochlear implant work?

With a Cl, you will wear a plastic earpiece with a tiny microphone. This is attached to a speech or sound box. The sound box may be worn on your belt or placed inside your pocket. During surgery, electrodes are put into your cochlea. A receiver is put under the skin behind your ear. The receiver is a listening tool and it works together with a transmitter. The transmitter is a round plastic coil that is worn outside your ear. Your doctor may decide that you need a Cl for one or both ears.

A Cl is different from a hearing aid. Hearing aids make sounds louder so that a damaged ear may hear them better. A Cl sends messages to your brain to help you understand sounds. It also may help you better understand speech and lip movements.

A Cl helps you understand sound by doing the work of the damaged hair cells. It changes sounds into signals that go to your hearing nerve and brain directly. The microphone receives sounds and sends them to the speech or sound box. The box changes the sounds into electric signals. These signals are sent through the transmitter to the receiver. The receiver sends the signals to the electrodes in your cochlea. Your cochlea sends the signals to your hearing nerve, which then sends them to your brain.

What tests may I need before getting a cochlear implant?

Your caregiver may test your ears to see if a Cl will be helpful to you. These tests may also help your caregiver choose which ear to use. He may also decide that you should have a Cl in both ears. You may need any of the following tests:

  • Hearing test
  • Auditory Brainstem Response (ABR) test
  • Blood test
  • Imaging test: This test takes pictures of your inner ear. You may be given dye before the pictures are taken. The dye may help your doctor see the pictures better.

Computed tomography scan: This test is also called CT scan. It is used to see if the structure of your inner ear is normal. It can also help your health care providers plan your surgery and choose the best Cl for you.Magnetic resonance imaging: This is also called MRI. MRI helps your doctor see if you have other ear problems, such as not having a hearing nerve.

For more information about DMC Sinai-Grace Hospital’s audiology and hearing services or to make an appointment, call 313-966-4725.