The temporal representation of speech in a nonlinear model of the guinea pig cochlea.
The temporal representation of speechlike stimuli in the auditory-nerve output of a guinea pig cochlea model is described. The model consists of a bank of dual resonance nonlinear filters that simulate the vibratory response of the basilar membrane followed by a model of the inner hair cell/auditory nerve complex. The model is evaluated by comparing its output with published physiological auditory nerve data in response to single and double vowels. The evaluation includes analyses of individual fibers, as well as ensemble responses over a wide range of best frequencies. In all cases the model response closely follows the patterns in the physiological data, particularly the tendency for the temporal firing pattern of each fiber to represent the frequency of a nearby formant of the speech sound. In the model this behavior is largely a consequence of filter shapes; nonlinear filtering has only a small contribution at low frequencies. The guinea pig cochlear model produces a useful simulation of the measured physiological response to simple speech sounds and is therefore suitable for use in more advanced applications including attempts to generalize these principles to the response of human auditory system, both normal and impaired.
Holmes
Stephen D
SD
School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. s.d.holmes@bham.ac.uk
Sumner
Christian J
CJ
O'Mard
Lowel P
LP
Meddis
Ray
R
D000818:Animals; D001489:Basilar Membrane / Q000502:physiology; D003051:Cochlea / Q000502:physiology*; D003056:Cochlear Nerve / Q000502:physiology; D003198:Computer Simulation; D005583:Fourier Analysis; D006168:Guinea Pigs; D006199:Hair Cells, Auditory, Inner / Q000502:physiology; D008144:Loudness Perception / Q000502:physiology; D017711:Nonlinear Dynamics; D010700:Phonetics; D010897:Pitch Discrimination / Q000502:physiology; D013018:Sound Spectrography; D013061:Speech Acoustics; D013067:Speech Perception / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*