UBC Theses and Dissertations
Digital software model of the human peripheral auditory system Alexandre, Eric Ernest
A model of the human peripheral auditory system is presented which is based on the anatomical and physiological data and mathematical presentations of the principal workers in the field. The physiological data come from human cadavers and cats in vivo. Since not all sections of the ear are understood with equal certainty, not all sections of the model are presented with the same degree of confidence. The model is used as a tool in carrying out experiments relating psychological performance with the underlying mechanisms. One interesting example is the localization of the mechanism producing combination tones within the human ear. Since the model is also capable of producing combination tones with all but one nonlinearity within the model eliminated, the primary auditory neuron is shown to be the nonlinearity causing the formation of combination tones. A plausible theory for this effect is presented and compared to psychological data. The model was programmed in Fortran IV and run on the IBM 360/67. Because of better I/O and display facilities for acoustic input, it is desirable to implement the model on a smaller computer such as the PDP-12. The large amount of storage for the present model prohibits this but simplifications are suggested so as to enable the implementation. The major discrepancy between the data produced by the model and physiological data results because the neural frequency selectivity of the model is inadequate. An inhibitory scheme to sharpen the selectivity is proposed.
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