What is a cochlear implant and how does it work?
A cochlear implant is an implantable electronic device that provides useful sound perception via electrical stimulation of the auditory nerve. The implant functions bypass the injured inner ear to directly stimulate the auditory nerve. Because most patients with severe sensorineural hearing loss still have an intact and functional auditory nerve, the implant is able to re-create the sensation of sound. These devices provide a wide range of sound information and performance. With time and appropriate rehabilitation, most users understand more speech than they did with their hearing aids and many are able to communicate by regular telephone. In select patients with partial deafness, newer technologies, such as combined electric and acoustic stimulation, can allow preservation of existing levels of hearing while using the implant to electrically stimulate those frequencies that are absent. UCSF offers three cochlear implant systems manufactured by Advanced Bionics, Cochlear Americas, and Med-El Corporation. The Implant System has three parts:
- Implantable Stimulator: The implantable stimulator consists of an electrode array and other electronic components. The electrode array is inserted into the cochlea to provide direct electrical stimulation to the auditory nerve. The electronic components are housed in a bio-compatible case which is surgically implanted under the skin and behind the ear selected for implantation. A magnet inside the case couples to the magnet in the headpiece.
- Headpiece / Transmitter: The headpiece and transmitter are worn externally on the head, and sit over the internal portion. The transmitter magnetically couples to the implanted stimulator. The microphone picks up sound in the environment and the transmission system sends the custom-coded signal across the skin to the implantable stimulator and electrode array. Electrical current is then sent to the auditory nerve which in turn sends signals to the brain where they are interpreted as sound.
- Speech Processor: The speech processor is worn externally on the ear or the body. The speech processor converts sound into a distinctive code. This code is transmitted through the headpiece/coil across the skin via radio waves to the implantable stimulator.
Will a cochlear implant help me?
A Cochlear Implant May Help You If You:
- Cannot understand most phone conversations
- Need closed captions when watching TV
- Rely heavily on lip reading
- Have limited social, educational or professional life
- Desire to improve hearing
- Have no medical contraindications
A Cochlear Implant May Help Your Child If He/She:
- Has delayed or lack of speech and language development
- Rarely responds to name
- Does not alert consistently to environmental sounds
- Lack of social interaction with children and adults
- Is enrolled in educational program and/or therapy emphasizing speech, language and audition
Am I an eligible candidate for cochlear implantation?
Criteria for Adults:
- 18 years of age or older
- Severe to profound hearing loss in both ears (70 dBHL or greater)
- Limited benefit from hearing aids
- Desire to improve hearing and realistic expectations
- Cannot understand most phone conversations
- Comprehension of TV primarily with use of closed captions
- No medical contraindications
- Rely heavily on lip reading
- Limited social, educational or professional life options
Criteria for Children:
- 12 to 23 months of age with profound hearing loss in both ears (90 dBHL or greater)
- 24 months to 17 years of age with severe to profound hearing loss in both ears (70 dBHL or greater)
- A general lack or plateau of auditory development
- Motivation to improve hearing and realistic expectations by the family
- Little or no benefit from appropriately fitted hearing aids
- No medical contraindications
- Appropriate educational placement for school-aged children