Sigfrid D. Soli Robert V. Shannon
House Ear Inst., 2100 W. 3rd St., Los Angeles, CA 91024
Research on the treatment of hearing impairment and deafness has, in recent years, increasingly focused on auditory prostheses that can aid speech communication in both quiet and noise. For these prostheses to be most effective, several research goals must be achieved. First, the residual capacity of the impaired auditory system must be determined. Next, the essential acoustic information for speech recognition must be characterized and re-coded to exploit the residual auditory capacity. Finally, algorithms and circuits that can extract and process this information are required. Efforts toward these goals in hearing aids and in cochlear and brainstem implants will be described. The binaural directional hearing capacity of individuals with sensorineural hearing impairment has defined the main focus of this hearing aid research because of its potential to improve speech communication in noise. In this implant research, the channel capacity and channel interactions of the electrically stimulated auditory system have received major attention because of the effects of these interactions on speech coding for multi-electrode implants. Methods for characterizing the residual capacity of an individual, techniques for using residual capacity to aid speech communication, and results from perceptual tests obtained with real-time, laboratory-based processors will be discussed.