Ear dominance and intensity independence of dichotic chords

Abstract

Recent papers [Efron and Yund, Neuropsychologia 12, 249–256 (1974); Yund and Efron, Perception Psychophys. 15, 383–390 (1974); Deutsch, Nature 251, 307–309 (1974); J. Acoust. Soc. Am. 55, S18(A) (1974); Yund and Efron, Neuropsychologia 13, 137–150 (1975); Efron and Yund, Neuropsychologia 13, 151–161 (1975); House, J. Acoust. Soc. Am. 58, S54(A) (1975)] have called attention to an ear dominance in the perception of dichotic chords. The primary observation common to these studies is the report of a difference in the pitch mixture of two dichotic chords in which the ear-frequency relationship is reserved. For some subjects the mixture is dominated by the frequency of the tone to the right ear; for others by the left-ear tone; for still others the pitch mixture is unchanged by the ear-frequency relationship. When this ear dominance is coupled with a lateralization effect, an auditory illusion results. Efron and Yund (1974) produced lateralization by interaural intensity differences. In the Deutsch and House experiments lateralization of the chord is in the direction of the ear receiving the higher frequency tone. In addition to the phenomenon of ear dominance which determined the dichotic pitch mixture, Yund and Efron (1975) also reported that this pitch mixture is independent of interaural intensity differences over a surprisingly large range.