Measurement of pitch in speech: An implementation of Goldstein’s theory of pitch perception

Abstract

Recent developments in hearing theory resulted in the rather general acceptance of the idea that the perception of pitch of complex sounds is the result of the psychological pattern recognition process. The pitch is supposedly mediated by the fundamental of the harmonic spectrum which fits the spectrum of the complex sound optimally. The problem of finding the pitch is then equivalent to finding the best harmonic match. Goldstein described an objective procedure for finding the best fit for stimuli containing relatively few spectral components. He uses a maximum likelihood criterion. Application of this procedure to various data on the pitch of complex sounds yielded good results. This motivated efforts to apply the pattern recognition theory of pitch to the problem of measuring pitch in speech. Although the main line of Goldstein''s procedure was followed, some essential changes had to be made. In this implementation not all spectral components of the complex sound are classified as belonging to the harmonic pattern. A harmonics sieve was introduced to determine whether components are rejected or accepted at a candidate pitch. A simple criterion, based on the components accepted and rejected, led to the decision on which candidate pitch was to be finally selected. The performance and reliability of this psychoacoustically based pitch meter were tested in a LPC [linear predictive coding] vocoder system.