Pure-tone perception and ear advantages in dichotic listening

A same-different matching task was used to investigate how subjects perceived a dichotic pair of pure tones. Pairs of stimulus tones in four frequency ranges (center frequencies of 400–1,700 Hz), with separations between 40 and 400 Hzt were tested. Five types of test tones were matched to the stimulus pair: the stimulus pair presented again (control) or crossed over (same tones, different ears), the geometric mean of the two tones, or a binaural tone of the low or high tone of the pair. In the lowest frequency range and the highest with maximum separation, the crossed-over test tones were perceived as different from the same stimulus tones. A bias for perceiving the higher tone of a pair was evident in the frequency ranges with separations of 40-200 Hz. In the lowest frequency range, the bias was for perceiving the higher tone in the right ear. This restricted ear advantage in the perception of pure tones was not significantly related to the right-ear advantage in dichotic word monitoring.