Cochlear Implants

Topic Overview

What is a cochlear implant?

A cochlear implant is a small electronic device that can help "make" sound if you have severe or total hearing loss. The implant does the job of the damaged or absent nerve cells that in a normal ear make it possible to hear (auditory nerves). Cochlear implants can be programmed according to your specific needs and degree of hearing loss.

Who can benefit from a cochlear implant?

Cochlear implants may help people with severe or total hearing loss in both ears who do not get any benefit from hearing aids. Cochlear implants have been shown to improve a person's ability to understand speech and speak clearly. Unlike hearing aids, cochlear implants do not make sounds louder but improve how well you hear sound.

How does a cochlear implant work?

A cochlear implant consists of a:

• Microphone worn behind the ear, to pick up sound.
• Speech processor worn on the body. Some types may be worn behind the ear.
• Small device placed under the skin near the ear, with electrodes placed in the cochlea. This is the cochlear implant.

The microphone picks up sound and sends it to the speech processor, which changes the sound to information the cochlear implant can understand. The implant then tells the nerves in the ear to send a message to the brain. The message is understood as sound.

How do I best benefit from a cochlear implant?

Speech therapy will help you make the most of your cochlear implant. Training in listening, language, and speech-reading skills (paying attention to people's gestures, facial expressions, posture, and tone of voice) also help you.

Do cochlear implants have any complications?

Cochlear implants have a low rate of complications, which may include:

• Risks of surgery, such as infection and medicine that numbs your senses during surgery (general anesthesia).
• The implant moving out of its proper location. You may need a second surgery to relocate the implant.
• The implant not working. It may not work because it was made incorrectly or because of an injury to or problem within the ear.
• Twitching of the face (such as a tic) or not being able to move muscles in the face. This is uncommon and rarely permanent.

In July 2002, the U.S. Food and Drug Administration (FDA) released a public health notification on a possible link between cochlear implants and bacterial meningitis.¹ The U.S. Centers for Disease Control and Prevention (CDC) has looked into this and found:¹

• Bacterial meningitis happened more often in children with cochlear implants than in children the same age who did not have implants. Most of the cases of meningitis were caused by the bacteria S. pneumoniae.
• Children with an implant with a positioner were much more likely to get bacterial meningitis than children with other types of cochlear implants. A positioner is a piece inserted to make it easier for the implant to communicate with the ear. These types of implants are no longer used.
• Children with a cochlear implant who had inner ear malformations and cerebrospinal fluid leaks were at increased risk for bacterial meningitis.
• It is not clear whether removing the implant will lower the risk of meningitis, and experts have made no recommendations on removal.

The CDC and U.S. Food and Drug Administration (FDA) have recommended the following to decrease the risk of bacterial meningitis in people with a cochlear implant:²

• Review your or your child's pneumococcal vaccination record, and talk to your doctor about whether you need any more vaccinations.
• Recognize the signs of meningitis. These include high fever, headache, stiff neck, feeling sick to the stomach or vomiting, difficulty looking into bright lights, and sleepiness or confusion. A young child or infant might be sleepy, cranky, or eat less. If you see any of these signs, contact your doctor.
• Recognize the signs of an ear infection, including ear pain, fever, and eating less. If you see any of these signs, contact your doctor.
• Talk to your doctor about using antibiotics during cochlear implant placement, to prevent meningitis.

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Author:	Monica Rhodes	Last Updated: April 30, 2007
Medical Review:	Kathleen Romito, MD - Family Medicine Donald R. Mintz, MD - Otolaryngology
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