Ear dominance in 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 human listeners. In some conditions the stimulus was monaural; in others a tone of fixed, different frequency was simultaneously present in the contralateral ear. Center frequencies of 1.2, 1.7 and 3.2 kHz were investigated. A small but reliable discrepancy existed between just noticeable frequency differences obtained for the right and for the left ear in the monaural and in the dichotic conditions. 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. Implications of the relationship between the two types of functional asymmetry of the auditory system were discussed.