Cochlear Implants | What They Are And How They Help Restore Hearing

Cochlear implants are used for sensorineural hearing loss that doesn't respond to medications or other treatments. This type of hearing loss affects the inner ear or auditory nerve in such a way that electrical impulses are not able to reach the brain. A common cause of this type of hearing loss is hair cell damage in the inner ear that leaves nerve fibers still functional. The implant bypasses the damaged cells and stimulates the nerves directly so sound can be transmitted.

In some cases, the auditory nerve fibers themselves are damaged so they cannot be stimulated, even by an implant. In fact, it is often difficult to know if the auditory nerves are functional until an implant is inserted, so outcome of the surgery is not always certain. In order to determine if you are a good match for implantation, you must be evaluated by an otologist, audiologist, and speech therapist.

Cochlear implants require surgery that lasts up to two hours that is done under general anesthesia so the procedure isn't to be taken lightly. The surgeon makes an incision behind the ear and drills into the bone to access the inner ear. Electrodes are placed inside and attached to the skull. Cochlear implants have two parts, one is internal and consists of a receiver, magnet, wires, and electrodes; the other is external and contains a cable, microphone, and sound processor inside an earpiece.

The external portion of the implant captures sound waves and transmits them through the cables directly to the nerves in the inner ears. While this procedure helps make conversations more distinct, even to the point of facilitating telephone conversations, hearing is far from normal. Users say the sounds have a mechanical quality to them and it actually takes quite a while to relearn sounds. Periodic visits with an audiologist are necessary in order to fine tune the amount of electrode stimulation so optimum sounds are produced. In fact, the implant is usually in place for about a month after surgery before it is turned on, so restoration of hearing doesn't happen right away.

As with any medical procedure, there are some risks associated with cochlear implants. The device could experience electrical or mechanical failure, your body could reject the implant, or infection could arise. This would require surgery to remove the device. In addition, the surgery itself poses some risk such as excess bleeding, injury to facial nerves, or complications from anesthesia.

For many, the risks are worth the benefits. Cochlear implants offer a wide range of results but most people experience at least some increased perception of sounds. Even if slight, this can assist with lip reading. Others have favorable results that enable them to hear over the telephone and participate in conversations. Everyone is different and the only way to know if you are a good candidate for cochlear implants is to discuss the possibilities with a medical professional.