The Rotary Bike-A-Thon Committee visited the Cochlear Implant Services at B.C. Children’s Hospital on April 22, 2009. During this visit the committee was given a tour of the Cochlear Implant Clinic. We learned that there is now a Provincial Early Hearing Program that screens all newborn babies. This initiative helps identify and diagnose hearing loss by the time babies are 3 months old, allowing for early intervention which is essential for their communication success. We were shown the soundproof booth and clinic offices with all the equipment needed to test infants/children. There was a demonstration of how to program a cochlear implant. In addition, we got to see a demo kit of what an internal cochlear implant and external speech processor looked like and how it worked.
The Cochlear Implant team consists of a pediatric otolaryngologist, clinical coordinator, three audiologists, a social worker, a psychologist and an administrative assistant. Any infant or child identified as having a severe to profound hearing in both ears can be referred to Cochlear Implant Services for a multidisciplinary team candidacy evaluation. This investigation is a very thorough procedure. The team looks at many aspects of the child's audiological (hearing), medical, and educational history, as well as current family situation. Furthermore, at any time the family may withdraw from the program if they feel a cochlear implant is no longer an option they wish to pursue.
What is a cochlear implant?
A cochlear implant is a device which directly stimulates the hearing nerve. It can provide sound for children who have a severe to profound hearing loss and/or receive little or no benefit from conventional hearing aids. Cochlear implant surgery is usually done after a child is at least one year of age.
What is the difference between a hearing aid and a cochlear implant?
Hearing aids make sounds louder. However, for children who have a severe to profound hearing loss, hearing aids may not be adequate in providing consistent access to sound for understanding of speech. Cochlear implants may be a good option for these children.
What are the parts of a cochlear implant?
A cochlear implant is a device that is implanted into the inner ear. A tiny electrode is surgically inserted into the cochlea, and a receiver is implanted behind the ear. In the picture below, you can see the electrode (3 in the picture) inserted into the inner ear (4 in the picture). The receiver (2 in the picture) is under the skin behind the ear.
Image courtesy of Cochlear Corporation
A child with a cochlear implant wears the sound processor on the body, or behind the ear (see number 1 for an example of an ear-level processor). The sound processor is attached to the transmitter coil (2), which is held on behind the ear by a magnet.
Image courtesy of Cochlear Corporation
How does a cochlear implant work?
1. Sound is picked up by the microphone in the sound processor.
2. The sound is converted into a digital signal, and processed.
3. The processed digital information is sent to the transmitter coil.
4. The transmitter sends the information by radio waves to the receiver below the skin.
5. The receiver sends the information to the electrode array in the inner ear.
6. The electrodes send signals to the hearing nerve, which is processed by the brain.