Future directions in the clinical application of multichannel cochlear prostheses [Abstract]

Three main areas of work at the University of Melbourne relating to the clinical application of multichannel cochlear prostheses will be discussed. Speech perception results for 40 children and adolescents implanted with the Nucleus multichannel device will be presented with an analysis of potentially predictive clinical factors. Overall results have shown that 60% of the children have developed useful open-set speech recognition ability without visual cues. Due to the improved speech perception for postlinguistically deafened adult cochlear implant patients, the multichannel implant has become a viable alternative for patients with some useful residual hearing. A "bimodal" speech processor which provides acoustic output for the residual hearing ear and electrical output for the cochlear implant will also be discussed. This device provides a flexible, programmable acoustic processor which can make use of feature coding aspects of the implant processing. The "bimodal" device has also addressed problems of incompatibility of the implant signal with the acoustic signal from conventional hearing aids. Results for the new "Spectral Maxima Speech Processor" (SMSP) will also be presented. The SMSP has shown improved speech perception performance in quiet and in noise when compared with the MSP (MULTIPEAK) system, currently in use with the Nucleus device. Results for four subjects with the SMSP showed mean scores of 57.4% for open-set monosyllabic words in quiet, and 78.7% for open-set sentences in a 10 dB signal-to-noise ratio