Cochlear Implant.

What is a Cochlear Implant

A Cochlear implant Cochlear Implant provides useful hearing and improved communication ability for people who have profound to total hearing loss. The research on Cochlear Implants was conducted about 30 years ago.

Since then, the system has advanced from a single- to a multiple-electrode or channel device that provides increased benefits to recipients.

Cochlear implantation has achieved recognition as an approved medical procedure for the treatment of profound sensorineural hearing loss in adults and children. Currently there are over 6000 adults and 4000 children and teenagers worldwide using a Nucleus Cochlear Implant System. Many profoundly hearing impaired individuals view the Cochlear Implant as a tool to interact with the hearing world and broaden their educational, occupational and social opportunities.

How is it different from a hearing aid or other devices that help people hear ?

Hearing aids and other similar devices are amplifiers. They are designed to make sounds louder or clearer so that hearing impaired people receive more sounds. Many people are deaf because their inner ears have been damaged by trauma, disease, or some other condition which causes a sudden or progressive hearing loss. Simply providing amplified sound through a hearing aid may not provide much benefit for individuals whose hearing loss is profound to local. A cochlear implant bypasses some of the damaged parts of the inner ear and can provide useful hearing for individuals who do not benefit from traditional hearing aids.

Who can benefit from using a Cochlear Implant ?

Many people with profound sensorineural hearing loss have some remaining auditory nerve fibres. Individuals can be tested to find out if these nerve fibres still function. If they do, the individual may be considered a candidate for a Cochlear Implant.

Adults of all ages benefit from Cochlear Implants. These include people who lost there hearing early in life and have had a hearing impairment for a long time.

In June 1990, the United States Food and Drug Administration (FDA) approved the Nucleus Cochlear Implant System for children aged 2 to 17 years. Strict requirements to demonstrate that the device is safe and effective for the use in children were met after more than two years of clinical investigations. The Nucleus Cochlear Implant System is the only Cochlear Implant in the world that has a full FAD approval for both adults and children. It is the most widely accepted system and it is used in over 45 countries worldwide.

General Criteria for Cochlear Implants.

What can be expected from using the Cochlear Implant ?

Recipients of the Nucleus Cochlear Implant System experience a sensation of sound.

The implant does not restore normal hearing but does improve the person's ability to hear environmental sounds, to hear rhythms and patterns of speech, and to use speech reading (lip reading) better.

What are the limitations of the Cochlear Implant ?

The Nucleus Cochlear Implant System is a technology that attempts to substitute the function of a complicated human sensory organ. Understandably, it has limitations.

The Cochlear Implant cannot help all profoundly hearing impaired people . Candidates are selected very carefully.  There are conditions that may prevent a person from qualifying for a Cochlear Implant.

The Cochlear Implant helps some people more than others.

Hearing sounds with a Cochlear Implant is different from normal hearing. Recipients have to learn to interpret sounds that they may hear. It may take some time and experience with the Cochlear Implant before recognition improves.

What is involved in the pre-operative assessment for the cochlear implantation ?

The implant centre conducts a careful evaluation to determine if an individual is an appropriate Cochlear Implant candidate. Audiological tests establish the level of hearing loss. Hearing aids and other devices are fitted to establish whether or not these devices might be beneficial. Each individual is counselled regarding the potential benefits and limitations of the Cochlear Implant. If the audiological tests indicate that the person might be a candidate, medical tests are performed. X-rays are taken to see if the cochlea is suitable for an implant. A promontory test may also be performed to determine if electrical stimulation of the auditory nerve (hearing nerve) will result in sound.

General tests are also performed to ensure that the individual can successfully undergo general anaesthesia and surgery.

The implant team will terminate the evaluation process if either they or the individual determine that he/she is not an appropriate candidate.

What are the risks of Cochlear Implant surgery ?

The primary risks of Cochlear Implant surgery are the same basic risks associated with any type of surgery that requires general anaesthesia. There are also a few specific risks related to operating on this section of the head. These risks include inflammation, infection, disturbance to the facial nerve, stiffness or numbness around the ear, disturbance of taste or balance, and noticeable change in tinnitus (head noise).

Although it is important to be aware of the possibility of these complications, the fact is that there have been few significant negative side effects from the surgery in the individuals who have received the Nucleus Cochlear Implant.

How much does a cochlear implant cost ?

Like any sophisticated medical device and procedure, cochlear implantation is not inexpensive. However, one should bear in mind that the Nucleus Cochlear Implant System can provide to an individual over a lifetime.

Generally there costs are associated with the pre-implant evaluation, the device, surgery, post-surgical fitting and rehabilitation to be taken into consideration. For example, the range of costs for cochlear implantation in the U.K. is from 25,000 to 35,000, but this may vary from clinic to clinic and from country to country.

The Cochlear Implant System.

The entire cochlear implant system [D]


The Nucleus 22 Channel Cochlear Implant System is shown above. The various components are: 1. The electrode array (which is placed in the inner ear). 2. The receiver for the electrode array. 3. The speech processor, a small electronics package that typically is placed in the wearer's pocket. 4. Transmitting coil and 5. Microphone, both of which are worn behind the ear.

this is a human skull [D]This is side of the head with the cochlear [D]



Today, cochlear implant devices are very sophisticated. The multichannel implant stimulates the hearing nerve in a variety of places to give information about pitch, which is essential for understanding speech. The externally worn processor is designed to incorporate advances in technology, so there is no need to wait for next year's upgrade. The sooner the person receives the implant after becoming deaf the better he/she will do with the implant
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