Pitch of noise bands.

Abstract

Ten subjects were asked to produce octave judgments, i.e., one octave above and one octave below a standard stimulus, with bands of low-pass and high-pass noise as well as sinusoids. For example, given a specific low-pass noise band as a standard, subjects adjusted the cutoff frequency of a second low-pass noise band so that its pitch was 1 oct above that of the standard. Results indicate that bands of noise have a pitch and that the pitch is correlated with cutoff frequency. For low-pass noise, there seemed to be a relatively linear relation between pitch and cutoff frequency from 80- to 10 000-Hz cutoff, whereas the linear relation for high-pass noise holds only for a restricted frequency range, 600–10 000 Hz. The pitch of both types of noise stimuli degenerates above 10 kHz, possibly because of limited earphone response and a rising threshold of hearing. More difficult to explain is the static and vague pitch of high-pass noise at low cutoff frequencies. A discussion of several mechanisms is included.