Abstract
The over‐all loudness of a pair of equally loud tones presented dichotically, a different frequency to each ear, is independent of the frequency separation between the two tones. This rule applies over the whole range of frequency separations tested, from 0 Hz to several thousand hertz; hence, dichotic tone pairs are just as loud as a binaural pair (same frequency to each ear). Both binaural and dichotic pairs, however, are generally less than twice as loud as a component presented by itself. The over‐all loudness is invariant even though at narrow frequency separations the components of a dichotic pair interfere with each other so that each component is softer when heard in the presence of the other than when heard by itself. At wide separations, where two distinct auditory images are reported, the loudness of a component is the same whether presented with or without the contralateral tone.