COCHLEAR IMPLANTS
More information
What is a cochlear implant?
A cochlear implant (bionic ear) is a surgically implanted device for the hearing-impaired. It is the first medical technology able to functionally restore a human sense - hearing. Unlike a hearing aid that amplifies sound to make it loud enough for an impaired ear, a cochlear implant bypasses the damaged area and sends sound signals directly to the auditory nerve. A cochlear implant consists of an internal and an external component.
The Internal Component has two main parts (neither are visible from the outside):
- A receiver-stimulator [3] placed under the skin behind the ear
- An electrode array [4] sitting within the inner ear
The External Component has two main parts:
- A speech processor [1] which may be worn behind the ear or on the body
- A transmitter coil [2]
How does a cochlear implant work?
Cochlear implants allow different parts of the inner ear to respond to different frequencies (pitch) of sound. The electrode array has individual electrodes which are placed within the inner ear. Each stimulates a different section of the inner ear corresponding to different frequencies.
When sound reaches the speech processor it is broken down into its component frequencies. This information is then passed to the transmitter coil and sent to the implanted receiver-stimulator. The receiver-stimulator sends this frequency information to the appropriate electrodes in the inner ear. This signal stimulates the inner ear nerves and the information is passed to the brain.
When is a cochlear implant considered?
A cochlear implant may benefit people who have a severe to profound sensori-neural, or inner ear hearing loss. Many people with nerve deafness actually have an inner ear hearing loss. A cochlear implant may also be appropriate when conventional hearing aids no longer provide enough sound information. This may include people with a progressive or sudden hearing loss. People considering a cochlear implant usually need to have had some hearing in the past and have developed spoken language skills.
There are very few factors that prevent cochlear implantation. Frailty, other medical problems, language difficulties and previous surgery may be an impediment.
Our centre is structured to provide cochlear implantation services to adults only. Children's cochlear implantation services are available through the Womens and Childrens Hospital.
What is the process of cochlear implantation?
Before Surgery
If you are considering a cochlear implant you will firstly need to be assessed by one of our surgeons. This medical assessment will determine if a cochlear implant may be beneficial and determine whether there are medical factors that would prevent implantation. After the inital assessment, our audiologists will conduct a hearing assessment. This may involve several visits over a period of time to accurately assess your level of hearing and communication.
An important part of this process is to determine what outcome can be realistically expected as it varies from person-to-person.
An opportunity will be provided for you to meet with people who have already received a cochlear implant and to share their experiences.
The Operation
We perform the surgical procedure at St Andrews Hospital, one of Adelaides premiere major private hospitals, located on South Terrace, Adelaide. The operation generally takes 2 to 3 hours and is performed under a general anaesthetic.
» » More detailed information on cochlear implant surgery.
Following Surgery
A few days after the operation an "Telemetry" check is performed to ensure the device is working as expected. Several weeks are then allowed for healing to occur prior to beginning the switch-on process.
The switch-on process involves around ten 1 to 2 hour visits with our audiologists over a 4 week period to tune the cochlear implant to your requirements. The aim is to fine tune the implant to maximize the amount of useful sound information you receive.
Ongoing Tuning
An average of 2 to 3 visits a year are required for ongoing tuning. Many recipients report changes and indeed improvement in their hearing over several years, hence the need for ongoing care.
Expected outcomes
A cochlear implant does not provide normal hearing and the degree of benefit varies considerably between individuals.
Generally, the results are best when the potential recipient already has good spoken language skills. Many recipients develop the ability to understand speech well using a cochlear implant alone. Others find it a benefit if used in conjunction with either lip-reading or a hearing aid in the opposite ear. Other advantages include an improved awareness of environmental sounds.
In ALL cases a successful outcome requires a strong commitment from both the recipient and their family to work hard through the switch on and rehabilitation process. A Cochlear implant is not a plug in and switch on device. There is a considerable learning process that needs to be undertaken.
This learning, training and improvement process is initially intensive and can continue throughout life.