Hearing the Subtleties

August 15, 2007

Hearing the Subtleties

Cochlear implants are electronic devices designed to produce useful hearing sensations for people with severe to profound hearing loss. An implant combines an externally worn microphone, sound processor and transmitter system with a receiver under the skin and an electrode array inside the inner ear--called the cochlea.

Did you know?

Nearly 10 percent of people in the U.S. have some degree of hearing loss. Two to three out of ever 1,000 children in the U.S. are born deaf or hard-of-hearing. Nine out of every 10 children who are born deaf are born to parents who can hear.
Source: National Institute on Deafness and Other Communications Disorders

Unlike hearing aids that rely mostly on amplifying sound, a cochlear implant bypasses the damaged portions of the ear and directly stimulates the auditory nerve. The brain then interprets these signals as sound. But such implants don’t yet replicate the subtle, tonal qualities of language and music. Electrical and computer engineering Professor Leslie Collins, a specialist in signal processing who has already made significant contributions to cochlear implant technology, is exploring methods to make implants provide a broader, more complex array of sounds.

Collins’ approach is to enhance the way the implant processes sound. Her research shows that using variable electrical pulse rates to represent frequency changes in speech and sounds may increase the breadth of information transmitted to the brain. This could result in a more realistic hearing experience for the implant wearer. In addition, she is exploring new ways to ‘tune’ or refine cochlear implant function based on the person’s own, measurable response to their device’s electrical stimulation. Her research is funded by the National Institutes of Health.