Cochlear Implants: Signal Processing and Speech Perception

Several million Americans today have profound hearing loss, and for years they had to rely on conventional hearing aids. Although hearing aids have been found to benefit hearing impaired individuals who suffer mild to moderate deafness, they do not seem to provide much benefit to individuals with profound (sensorineural) deafness. Today, a prosthetic device, a cochlear implant, can be implanted in the inner ear to restore partial hearing to profoundly deaf people. Cochlear implants are now established as a new option for individuals with profound hearing impairments. Most individuals who are implanted with cochlear prosthesis are able to understand speech without lipreading and can communicate over the phone. This article presents an overview of cochlear implants, describing the signal processing and stimulation strategies they employ and summarizing key research findings.