Dichotic listening

The number of correct responses (CR) was submitted to ANOVAs. First, an ANOVA was performed with the between-subjects factor Group (right tinnitus-simulated RSIM, or left tinnitus-simulated LSIM), and the within-subjects factor Ear/Hemisphere of recall: right ear/left hemisphere (RE/LH) and left ear/right hemisphere (LE/RH).

This ANOVA revealed that participants responded more accurately when the stimuli were presented to the RE/LH (CR = 15.65) than when they were presented to the LE/RH (CR = 11.30), F(1, 18) = 15.65, p < .001. This result did not differ according to the group. Because we wanted to insure that lateral differences did exist for each group, we performed contrast analyses comparing LE/RH and RE/LH performance in each group. These analyses revealed a RE/LH advantage in both RSIM, F(1, 18) = 6.95, p < .02, and LSIM, F(1, 18) = 8.75, p < .01.

Following the same logic as in Experiment 1, we performed a second analysis on the laterality index, comparing RSIM and LSIM participants. This ANOVA demonstrated no significant effect of the factor Group, F < 1.

A third ANOVA was performed on the number of correct responses with Group as between-subjects factor, and Ear/Hemisphere of recall and Rank of the word recalled within each triplet (R1, R2, and R3) as within-subjects factors. This analysis confirmed the RE/LH advantage observed above, F(1, 18) = 6.85, p < .02, and further revealed that participants better recalled the last word of the triplet (R3 = 5.3) than the other two (R1 = 3.75; R2 = 3.8), F(2, 36) = 10.78, p < .0003.

Finally, we performed an ANOVA on the side-inversion errors as defined in Experiment 1. This ANOVA included the factor Group as between-subjects factor and the factor Inversion-Side as within-subjects factor. No significant effect was revealed by this analysis.