The effect of self-reported handedness on auditory binaural integration and separation

Abstract

This study examined the influence of self-reported handedness on auditory binaural integration and separation performance using the Dichotic Digits Test (DDT) in normal-hearing young adults. Dichotic listening tasks provide insight into hemispheric lateralization and auditory processing, yet the specific contribution of handedness to auditory laterality remains unclear. A quantitative, cross-sectional comparative design was employed, including twenty-eight participants aged 19-24 years (16 right-handed, 12 left-handed). Although the sample size was modest, determined by feasibility constraints rather than power sufficiency, the results provide preliminary evidence that handedness modulates auditory performance. Participants completed the DDT under three conditions: binaural integration, directed attention separation, and undirected attention separation. Laterality indices were calculated, and t-tests compared ear advantage within and between groups. No significant ear advantage was observed within groups (p > 0.05); however, between-group analyses revealed significant effects, with right-handed participants demonstrating a right-ear advantage during undirected attention (p = 0.02) and integration (p = 0.005), while left-handed participants showed a left-ear advantage during integration (p = 0.04). These findings suggest that handedness influences auditory lateralization, particularly under higher cognitive or attentional demand. Findings may inform the clinical interpretation of dichotic listening assessments, highlighting the importance of considering handedness in evaluating auditory processing and hemispheric asymmetry.