Accuracy of binaural loudness matching with repeated short tones.

Abstract

Subjects were required to match tones in one ear to the loudness of the same tones in the other ear. The standard deviations of the matched values were used as a measure of the binaural intensity-disparity threshold, and the avg. of the matched points was used as a measure of equal loudness at the 2 ears. Repeated short tones were matched more accurately than steady tones, although the repetition rate of the tones had little effect on accuracy of matching. Tones of 20 msec. duration were matched less accurately than either longer or shorter tones, and loudness matching was as accurate with one msec. tones as with 200 msec. tones. Both frequency and intensity had little effect on the disparity threshold. Subjects can match their own observations more accurately than they can match other subjects'' observations. Differences between subjects in the point of subjectively equal loudness were large, and made it questionable that intensity differences alone can account for localization of sound sources even at the higher frequencies.