Cochlear Implants

What is a cochlear implant?

• A cochlear implant (CI) 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 CI if you are very hard of hearing and hearing aids do not help. Your caregiver may also decide that you should have a CI if you are deaf.
  
  
• With a CI, you will wear a plastic ear piece with a tiny microphone. This is attached to a speech processor and a receiver. During surgery, electrodes (wires) 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 caregiver may decide that you need a CI for one or both ears.

How does a cochlear implant work?

• A CI helps you understand sound by doing the work of the damaged hair cells. It changes sounds to signals that go to your hearing nerve and brain directly. The microphone receives sounds and sends them to the speech processor and a receiver. 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.
  
  
• A CI is different from a hearing aid. Hearing aids make sounds louder so that a damaged ear may hear them better. A CI sends messages to your brain to help you understand sounds. It also may help you better understand speech and lip movements.

What tests may I need before getting a cochlear implant?

Your caregiver may test your ears to see if a CI 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 CI in both ears. You may need any of the following tests:

• Audiogram: This is a set of tests that measures how well you hear sounds and words. An audiogram may include the following:
  
  
  • Acoustic reflex test: This test measures how much certain muscles in your ear shorten or tighten when you hear sounds.
    
    
  • Pure tone test: During this test, tones or sounds are played to show caregivers what you can and cannot hear.
    
    
  • Speech discrimination test: You will be asked to repeat words. This test helps caregivers find out more about your hearing limits.
    
    
  • Speech reception threshold test: This test shows how well you hear soft sounds. It also helps caregivers learn at what point you can no longer hear sound.
    
    
  • Tympanogram: A tympanogram is a test to see how well your ear reacts to sound and different pressures. Caregivers will put a probe (small tube) in your ear. They will look at how well your eardrum moves. They will check the pressure behind your eardrum. If your ears are not working right, the pressures in front and behind your eardrum will be different. During the test, you will hear some short, loud beeps. This is to test how well your ear muscles work to protect your inner ear. Caregivers can see if you have fluid in your ear or other middle ear problems.
  
  
• Auditory brainstem response (ABR) test: This test plays a series of clicks through headsets on your ears. A special machine is used to measure how your cochlea and nerves react to the clicks.
  
  
• Blood tests: You may need blood taken to give caregivers information about how your body is working. The blood may be taken from your hand, arm, or IV.
  
  
• Imaging tests: These tests take pictures of your inner ear. You may be given dye before the pictures are taken. The dye may help your caregiver see the pictures better. People who are allergic to shellfish (lobster, crab, or shrimp) may be allergic to some dyes. Tell your caregiver if you are allergic to shellfish, or have other allergies or medical conditions.
  
  
  • Computed tomography scan: This test is also called CT scan or CAT scan. It is used to see if the structure of your inner ear is normal. It can also help your caregivers plan your surgery and choose the best CI for you.
    
    
  • Magnetic resonance imaging: This is also called MRI. MRI helps your caregiver see if you have other ear problems, such as not having a hearing nerve.

What happens during cochlear implant surgery?

• You will be taken to the room where your surgery will be done. You will lie on your back during surgery. You will receive anesthesia medicine to keep you asleep and free of pain during your surgery. A small amount of your hair may be shaved and your skin will be cleaned. Your caregiver will fold your outer ear inwards to cover your ear opening.
  
  
• Your caregiver will cut behind your ear along your hairline. Your caregiver will then lift up a flap of skin. A hole will be drilled through your skull (head bone). Your caregiver may need to remove bone to create a space to put the receiver. The electrodes will be placed into your cochlea. The receiver is kept in place with stitches (thread) attached to your skull. Your cut will be closed with stitches.

What are the risks of having cochlear implant surgery?

• After your surgery, you may not heal properly. You may start to feel dizzy. Around the cut, you may get an infection or some nearby skin may die. Your CI may not be in the right place or it could stop working. If this happens, you may need to have another surgery to fix it. During surgery, parts of the ear may be damaged. A nerve may be injured which may cause you to lose feeling in your face. You may also be unable to move parts of your face.
  
  
• After surgery, you may get meningitis. Meningitis is a serious infection around your brain and spinal cord. Without surgery, your hearing problems may get worse. You may also become deaf. Ask your caregiver if you are worried or have questions about your surgery, condition, or care.

What should I expect after having cochlear implant surgery?

• Right after your surgery: You will be taken to a room where you can rest until you are awake. Do not try to get out of bed until your caregiver says it is OK. You may then be able to go home or you may be taken to your hospital room. You will have a bandage behind your ear to keep the wound clean and dry. This will be removed when your caregiver checks your wound.
  
  
• Follow-up visits: You will need to see your caregiver so he can check your CI. You may need to come back for hearing tests to check if your CI is working properly. Make sure to keep all your planned visits with your caregiver. Write down any questions you may have. This way you will remember to ask these questions during your next visit.
  
  
• Rehabilitation: After you receive your CI, you will need to go to rehabilitation. Rehabilitation is a type of therapy that helps you learn how to use your CI. This training will help your brain understand the electric messages as speech or sound.

Where can I find support and more information?

Having a CI may help you feel better about yourself. It may help you feel more confident. You may also be more social around other people. You may feel less sad. You may also have more control over your thoughts, actions, and emotions. Contact any of the following for support or more information about cochlear implants:

• Alexander Graham Bell Association for the Deaf and Hard of Hearing
  3417 Volta Place NW
  Washington , DC 20007
  Phone: 1- 202 - 337-5220
  Web Address: http://www.agbell.org
  

• Better Hearing Institute
  515 King Street, Suite 420
  Alexandria , VA 22314
  Phone: 1- 703 - 684-3391
  Web Address: www.betterhearing.org
  

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.