Ear dominance of dichotic chords and ear superiority in frequency discrimination.

Abstract

Frequency-discrimination thresholds were determined for pure tones presented either to the right or to the left ear of experienced listeners. In some conditions the stimulus was monaural, whereas in others a tone of fixed, different frequency was simultaneoulsy present in the contralateral ear. Center frequencies of 1.2, 1.7, and 3.2 kHz were investigated. Results reveal a small but reliable discrepancy between just noticeable frequency differences obtained for the right and for the left ear, both in the monaural and in the dichotic conditions. Furthermore, the direction and the degree of asymmetry with respect to the frequency resolving power of the two ears showed a correlation with the direction and the degree of ear dominance for the pitch of dichotic two-tone complexes. [See Efron and Yund, J. Acoust. Soc. Am. 59, 889–898 (1976).] Implications of the relationship between the two types of functional asymmetry of the auditory system are discussed.