What is a cochlear implant?
A cochlear implant is an electronic medical device that replaces the function of the damaged inner ear. Unlike hearing aids, which make sounds louder, cochlear implants do the work of damaged parts of the inner ear (cochlea) to provide sound signals to the brain.
If you have a severe to profound sensorineural hearing loss in both ears and don’t get much benefit from hearing aids, you might be a candidate for a cochlear implant. This means a hearing loss in both ears of greater than 70 bB and poor speech discrimination (less than 50% correct on a sentence recognition test) in the better-hearing ear. To determine whether you are a candidate, you’ll have to have a complete evaluation, including hearing tests, a CT and MRI scan of the ear.
Cochlear Implant Procedure
Many people suffer hearing loss because their hair cells in the inner ear or (or cochlea) are damaged. The cochlear implant enables the sound to be transferred to your hearing nerves and enables you to hear. The process is described below:
A sound processor worn behind the ear or on the body, captures sound and turns it into digital code. The sound processor has a battery that powers the entire system.
The sound processor transmits the digitally-coded sound through the coil on the outside of your head to the implant.
The implant converts the digitally-coded sound into electrical impulses and sends them along the electrode array placed in the cochlea (the inner ear).
The implant’s electrodes stimulate the cochlea’s hearing nerve, which then sends the impulses to the brain where they are interpreted as sound.
The cochlear is found in the inner ear. The cochlear consists of three different canals. The middle canal is the organ of hearing and consists of sensitive hair cells. The hair cells can be stimulated electrically, and forward the signal to the nerves and then on to the brain. In most cases of deafness, the hearing nerve still remains functional, but the hair cells have been damaged or even lost.
In a Cochlear implant system, sound enters a microphone and travels to an external mini-computer called a “sound processor”. The sound is processed and converted into digital information. This digital information is sent over a transmitter antenna to the surgically implanted part of the system. The implant turns the sound information into electrical signals that travel down to an electrode array inserted into the tiny inner ear, or cochlear. The electrodes directly stimulate the auditory nerve which in turn sends sound information to the brain. Dodging the damaged inner ear, the cochlear implant provides an entirely new mechanism for hearing.
What are the benefits of a cochlear implant?
Many adults with cochlear implants report that they:
Hear better with a cochlear implant than with a hearing aid
A previous study has shown that people with cochlear implant achieve an average of 80% sentence understanding, compared with 10% sentence understanding for hearing aids.
Can focus better when in noisy environments
This allows them to have conversations with people across meeting tables, in restaurants and other crowded places.
Reconnect with missed sounds that they could not hear before their cochlear implant.
Feel safer in the world as they can hear alarms, people calling out and approaching vehicles.
Talk and hear on the phone
Before and After Photo: