Responses of Cochlear Nucleus Neurons to Speech Signals: Neural Encoding of Pitch, Intensity and other Parameters

Investigations of responses of neurons in the auditory system to human speech stimuli are believed to be significant both from a basic and from an application point of view. In the former, the spectrally and temporally complex speech signals may be well suited to reveal complex nonlinear signal processing characteristics of the auditory system. In the latter, neural data may provide a useful reference for an ideal auditory prosthesis. Responses of primary auditory nerve fibers to elementary human speech stimuli have been relatively well documented (e.g., Sachs and Young, 1979; Carlson and Grandstrom, 1982; Delgutte and Kiang, 1984). In contrast, much less is known about responses to speech stimuli at the level of the cochlear nucleus although there have been several reports on this subject (e.g., Moore and Cashin, 1974; Kiang, 1975; Caspary et al., 1977; Rupert et al., 1976). Recently, Palmer et al. (1986) and Blackburn et al. (1986) investigated “primarylike” neurons in the anteroventral cochlear nucleus (AVCN) using vowel stimulation. The present paper reports results from our studies focused on the posteroventral and dorsal cochlear nuclei (PVCN and DCN) under stimulation with vowels and consonant-vowel syllables.