Cochlear Implants

From the site: http://www.nidcd.nih.gov/health/hearing/coch.asp 

 

What is a cochlear implant?

A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure). An implant has the following parts:

• A microphone, which picks up sound from the environment.
• A speech processor, which selects and arranges sounds picked up by the microphone.
• A transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses.
• An electrode array, which is a group of electrodes that collects the impulses from the stimulator and sends them to different regions of the auditory nerve.

An implant does not restore normal hearing. Instead, it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech.

 

How does a cochlear implant work?

A cochlear implant is very different from a hearing aid. Hearing aids amplify sounds so they may be detected by damaged ears. Cochlear implants bypass damaged portions of the ear and directly stimulate the auditory nerve. Signals generated by the implant are sent by way of the auditory nerve to the brain, which recognizes the signals as sound. Hearing through a cochlear implant is different from normal hearing and takes time to learn or relearn. However, it allows many people to recognize warning signals, understand other sounds in the environment, and enjoy a conversation in person or by telephone.

 

How does someone receive a cochlear implant?

Use of a cochlear implant requires both a surgical procedure and significant therapy to learn or relearn the sense of hearing. Not everyone performs at the same level with this device. The decision to receive an implant should involve discussions with medical specialists, including an experienced cochlear-implant surgeon. The process can be expensive. For example, a person’s health insurance may cover the expense, but not always. Some individuals may choose not to have a cochlear implant for a variety of personal reasons. Surgical implantations are almost always safe, although complications are a risk factor, just as with any kind of surgery. An additional consideration is learning to interpret the sounds created by an implant. This process takes time and practice. Speech-language pathologists and audiologists are frequently involved in this learning process.

Aubrey will be receiving a device called the Nucleus 5, which is the latest and greatest technology from Cochlear Company. Here is an overview - compliments of  http://products.cochlearamericas.com/cochlear-implants/how-nucleus-5-works:

 

Nucleus^® 5 is Designed to Mimic Natural Hearing

Deep in your ear is a remarkable pea-sized structure called the cochlea. The cochlea is fully developed at birth. Tiny, delicate hair cells in the cochlea communicate sound signals to your brain, allowing you to hear different pitches and sounds. If these delicate cells are damaged, you can lose some or all of your ability to hear.
Cochlear implants are designed to compensate for the damaged cells, helping to restore your ability to perceive and understand sounds. A cochlear implant works by bypassing the damaged part of the ear and sending sound signals directly to the hearing nerve.

 

How Nucleus 5 works

 
1. The external sound processor captures sounds, then filters and processes the sounds.
2. The sound processor translates the filtered sounds into digital information, which is then transmitted to the internal implant.
3. The internal implant converts the digital information into electrical signals, and sends them to a tiny, delicate curl of electrodes that sits gently inside the cochlea.
4. The electrical signals from the electrodes stimulate the hearing nerve, bypassing the damaged cells that cause hearing loss, allowing the brain to perceive sound.

Here is an actual picture of all the parts:

Internally –  the electrode sits within the cochlea and is actually 22 electrodes. This is pushed (carefully) into the cochlea during surgery. This is attached to the receiver (first picture below), which is implanted just below the skin above the ear.



This is the electrode array 



Externally – a microphone to pick up sound and the speech processor to convert that sound into digital form.  The two parts are joined by a magnet in the receiver and transmitter across the skin.



Here are some links to videos to see how an implant works and a video of the surgical process:

http://www.youtube.com/watch?v=QpBbJealks0

http://www.5min.com/Video/Cochlear-Implant-Surgery-114223413