ABSTRACT

This paper outlines a ‘pulse ribbon’ model of hearing that attempts to provide a bridge between the output of the cochlea as observed in single fibers of animals and the sensations that humans hear when stimulated by complex sounds. The first two stages simulate the operation of the cochlea with a 24-channel filter bank and 24 pulse generators. Together they convert a sound into a set of 24 pulse streams, collectively referred to as a pulse ribbon. The remaining three stages transform the initial pulse ribbon into ‘aligned’, ‘spiral’ and ‘cylindrical’ pulse ribbons. The transformations are intended to characterise phase perception, pitch perception and timbre perception, respectively. Together they illustrate the kind of neural processing required to convert the output of the cochlea into auditory sensations. A set of experiments on monaural phase perception was performed to determine the appropriate properties for the phase transformation. They show that we hear between-channel phase changes as well as within-channel envelope changes.