Time vs Intensity in Sound Localization
Randolph H. Whitworth, Lloyd A. Jeffress · The Journal of the Acoustical Society of America · 1960
In 1927 Banister wrote, “If the intensities at the two ears are not equal, an observer may judge that the tone of low pitch is localized … (toward the louder side) … but with more careful observation, two sounds will, as a rule, be discriminated. …” Like many a sage remark, this one has gone unnoticed, and we continue to trade time and intensity. Or we let the second sound go unlocalized and complain when it causes variability in our data. The present study is concerned with this second sound. Subjects adjusted a delay line until a 500-cps tone (the pointer) supplied to them through it (and earphones) matched in localization another 500-cps tone (the signal). The two tones were presented alternately. Various combinations of interaural time and intensity differences for the signal tone were used. Two experienced subjects performed during one phase of the experiment and several naive subjects during another. The experienced subjects were able, after some practice, to respond at will to either of the two localizations. Their “time response” data closely resemble the data presented by Moushegian and Jeffress for one subject, and their “intensity response” data resemble in many respects (but not all) the data for two others. The findings are not explainable in terms simply of a peripheral “trading relation” between time and intensity. (This work was supported by the Bureau of Ships.)