Learn About Cochlear Implants
What is a cochlear implant?
A cochlear implant is a hearing device designed to bypass the damaged parts of the inner ear by electrically stimulating the hearing nerve. The nerve then sends a signal to the brain where it is interpreted as sound.
Cochlear implants provide an important option for children and adults with significant hearing loss who gain little or no benefit from hearing aids.
What does a cochlear implant look like?
A cochlear implant has both internal and external parts.
The internal part is put in place surgically under general anesthesia. It consists of:
- A receiver and magnet, placed under the skin behind the ear
- An electrode array (series of electrodes), placed in the cochlea.
The external part is worn behind the ear. It consists of:
- A sound processor powered by batteries (looks similar to a hearing aid)
- A cable and circular coil connected to the sound processor that is held on the head by a magnet.
How do we hear?
- Sound travels through the ear canal and reaches the eardrum
- Sound waves cause the eardrum to vibrate, setting the three tiny bones in the middle ear into motion
- This motion causes the fluid inside the inner ear (cochlea) to move the hair cells.
- The cochlear hair cells change the movement into electric impulses, which are then sent along the hearing nerve to the brain and interpreted as sound.
How does a cochlear implant work?
Click on the image below to see an animated Cochlear implant Video.
- Sound is received by the microphone of the sound processor
- The sound is processed into digital signals
- The digital signals are sent to the transmitter coil
- The transmitter coil sends the digital signals across the skin where it is converted into electrical signals by the internal device
- Electrical signals are sent to the electrode array to stimulate the hearing nerve fibres in the inner ear (cochlea)
- Signals are then sent via the hearing nerve to the brain and recognised as sound.
Who can benefit from a cochlear implant?
Children and adults with significant hearing loss who are not able to gain adequate hearing from hearing aids may benefit from a cochlear implant. SCIC provides assistance to babies, children, adults, and the elderly who were born with, or later developed, hearing loss.
Possible outcomes with a cochlear implant
- Improved ease of listening
- Increased confidence in social situations and in the workplace
- Increased ease of listening over distances
- Greater appreciation of music
- Children implanted at an early age develop speech and language
- Some people with a cochlear implant are able to use the telephone.
Cochlear Implants in Children
SCIC Medical Director A/Professor Catherine Birman gives a detailed overview of paediatric cochlear implants at: