Perceptual independence of pulse rates used in speech coding schemes for a multichannel cochlear implant
Wai Kong Lai, Y. C. Tong, J. Bruce Millar, G. M. Clark, Richard J. van Hoesel · The Journal of the Acoustical Society of America · 1989
Two of the most important electric signal parameters for presenting useful acoustic speech information to the University of Melbourne/Nucleus multichannel cochlear implant are electrode position and electric pulse rate. The possibility of using pulse rate to encode acoustic speech information was investigated in this study. A set of 16 (4×4) orthogonal stimuli comprising all possible combinations of four different pulse rates on each of two fixed bipolar electrode pairs was presented to three cochlear implant recipients for identification. Tests for perceptual independence in terms of information transmission indicate that the two pulse rates presented on each of the two electrode pairs were perceived as partially separable dimensions. It may therefore be possible to use individual pulse rates on different electrode pairs in a speech coding scheme to present further acoustic speech information to a multichannel cochlear implant. [Work supported by NIH Contract NOI-NS-9-2400 and NIH Grant NS21027.]