This chapter reviews a classical problem, perception of tones, and suggests that our understanding of this topic may be enhanced by considering it as part of a larger topic: that of perception of acoustic repetition. As we shall see, periodic sounds repeated at tonal and infratonal frequencies appear to form a single perceptual continuum, with study in one range enhancing understanding in the other.

Terminology

Some terms used in psychoacoustics are ambiguous. The American National Standards Institute (ANSI, 1976/1999) booklet Acoustical Terminology defines some basic technical words as having two meanings, one applying to the stimulus and the other to the sensation produced by the stimulus. The confusion of terms describing stimuli and their sensory correlates is an old (and continuing) potential cause of serious conceptual confusions – a danger that in 1730 led Newton (1952, p. 124) to warn that it is incorrect to use such terms as red light or yellow light, since “ … the Rays to speak properly are not coloured.” However, the ANSI definitions for the word “tone” reflect current usage, and state that the word can refer to: “(a) Sound wave capable of exciting an auditory sensation having pitch. (b) Sound sensation having pitch.” A similar ambiguity involving use of the same term to denote both stimulus and sensation is stated formally in the ANSI definitions for the word “sound.” The use of both of these terms will be restricted here to describe only the stimuli.