Factors affecting pitch judgments as a function of spectral composition.

Stimulated by a recent paper by Platt and Racine (1985), we discuss the factors that probably are involved in certain inconsistencies observed in pitch judgments of tones with different spectral composition. Typically, discrepancies reported in the literature are of the order of 10 cents in magnitude. We point out that measurement of such small pitch effects is heavily dependent on systematic individual differences, and that, when individual differences are averaged out (as is essentially the case in Platt and Racine's experiments), verification of the actual auditory stimulus sound pressure level (SPL) within a few decibels is necessary. Utilizing the virtual-pitch theory, we evaluate the effects of frequency, SPL, and earphone-frequency response. Furthermore, we present experimental and theoretical data on pitch of piano tones relevant to the problem. The study elucidates that, taking into account the factors mentioned, agreement between the various data considered, as well as theoretical understanding, actually is much better than would be apparent at first sight.