Large individual differences in minor ear output during dichotic listening.

Using dichotic consonant-vowel (CV) stimuli, 150 highly educated adults were segregated into two groups. In the high-output group (n = 63), the mean number of CV syllables reported by the minor ear was more than half that of the major ear, while for the low-output group (n = 87), it was less than one-fourth. The low minor ear performance of the latter group immediately disappeared when CV syllables were separated by 90 ms. These subjects (44 male, 43 females) were unaware of their temporary minor ear incapacities. Although the mechanism and brain laterality significance of this phenomenon remain to be clarified, preliminary research indicates that members of each of these two groups have other differences in common.