Pitch Associated with an Irregularity in the Phase Spectrum

Abstract

Consider a broad-band spectrum produced by periodically repeating a burst of a special noiselike waveform (a Huffman sequence). The noise has essentially a flat power spectrum over the major portion of the audio band. The phase spectrum of the noise is a monotonic function of frequency and is generally increasing at a constant rate except at one frequency region. In listening to this repeated waveform, one hears a low-quency buzz associated with the frequency of repetition. In addition, a clear pitch quality can be heard. This pitch corresponds in frequency to the region of the irregularity in the phase spectrum. This phase pitch is independent of the repetition frequency of the noise burst but can be moved up and down the frequency scale by using different noise waveforms, having irregularities in the phase spectra at different frequency regions. A demonstration of the effect will be presented. [This research was supported by the National Institutes of Health, Public Health Service, U. S. Department of Health, Education, and Welfare.]