ASA 15 - Octave Matching


Experiments on octave matching usually indicate a preference for ratios that are greater than 2.0. This preference for stretched octaves is not well understood. It is only partly related to our experience with hearing stretch-tuned pianos. More likely, it is related to the phenomenon we encountered in Demonstration 14, although in this demonstration the tones are presented alternately rather than simultaneously.

In this demonstration, a 500-Hz tone of one second duration alternates with another tone that varies from 985 to 1035 Hz in steps of 5 Hz. Which one sounds like a correct octave? Most listeners will probably select a tone somewhere around 1010 Hz.


D.Allen (1967), "Octave discriminibility of musical and non-musical subjects," Psychonomic Sci. 7, 421-22.

E.M.Burns and W.D.Ward (1982), "Intervals, scales, and tuning," in The Psychology of Music, ed. D.Deutsch (Academic Press, New York) pp. 241-69.

J.E.F.Sundberg and J.Lindqvist (1973), "Musical octaves and pitch," J. Acoust. . Soc. Am. 54, 922-29.

W.D.Ward (1954), "Subjective musical pitch," J. Acoust. Soc. Am. 26, 369-80.

Time Delay


A 500-Hz tone alternates with a stepwise increasing comparison tone near 1000 Hz. Which step seems to represent a "correct" octave? The demonstration is presented twice.