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Cochlear implant

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Ear anatomy

Overview

Cochlear implant

Information:

A cochlear implant is a small electronic device that helps people hear. It can be used for people who are deaf or very hard of hearing. A cochlear implant is not the same thing as a hearing aid because it is surgically implanted and works in a different way.

There are many different types of cochlear implants -- but they generally consist of several similar parts. One part of the device is surgically implanted into the temporal bone (the bone surrounding the ear). It consists of a receiver-stimulator, which accepts, decodes, and then transmits an electrical signal to the brain.

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The second part of the cochlear implant is an external device. This consists of a microphone/receiver, a speech processor, and an antenna. This portion of the implant receives the sound, converts the sounds into an electrical signal, and transmits it to the internal portion of the cochlear implant.

WHO USES A COCHLEAR IMPLANT?

Cochlear implants allow deaf people to receive and process sounds and speech. To a certain degree, they are devices that allow deaf people to "hear." However, it is important to understand that these devices do not re-establish normal hearing -- they are tools that allow sound and speech input to be processed and transmitted to the brain.

The criteria used to select appropriate candidates for cochlear implants are changing over time -- as both the technology changes, and our understanding of the brain's auditory (hearing) pathways improves.

Both children and adults can be candidates for cochlear implantation. They may have been born deaf or become deaf after learning to speak. Children as young as 1 year old are now candidates for this surgery. Although adult and pediatric criteria are slightly different, they are based on similar guidelines:

1. The patient should be completely or very-near completely deaf in both ears, and receive almost no improvement with hearing aids. Anyone who has adequate hearing with hearing aids is not a good candidate for cochlear implants.
2. The patient needs to be highly motivated, because after the cochlear implant is placed, there is a significant amount of learning that needs to occur in order to make proper use of the device.
3. The patient needs to have reasonable expectations for what will occur after surgery. The device does not restore or create "normal" hearing.
4. Children need to be enrolled in programs that help them learn sound-processing skills.
5. In order to determine if a patient is a candidate for cochlear implant, the patient must have a medical evaluation by an otolaryngologist (ear, nose, and throat doctor). This evaluation may include a CT scan or an MRI scan to evaluate the structures of the brain, and of the middle and inner ear.
6. Patients (especially children) may need psychological evaluation to determine if they are good candidates.