Dichotic listening with syllables: Effects of forced attention.

This study compares results from three dichotic listening experiments involving different methods of attention control. In each experiment, participants completed a dichotic listening task requiring two responses to syllables and we noted the order of report for the responses. In Experiment 1, participants reported from a specific ear first in trial blocks. In Experiment 2, an arrow cue indicated the ear of first report. In Experiment 3, a tone was presented to the ear of first report. Free recall in which participants reported the two syllables in any order was also included as a baseline. Results indicated a tendency to report from the right ear first in free recall, producing more reports from that ear, reflecting a right ear advantage (REA). In all cueing conditions, an overall REA emerged but it shifted to a left ear advantage (LEA: more reports from the left ear) when the left ear was cued. Additionally, larger laterality scores ([Right - Left]/[Right + Left]) for the conditions where the right ear was cued, relative to where the left ear was cued, suggests that attention control is limited in overriding the structural auditory asymmetries. We discuss the implications of these results for models of dichotic listening.