Fig. 5.
Binaural versus monaural sensitivity. A–D: azimuth tuning curves of 4 different neurons from hearing loss (HL) rabbits measured at near-threshold level under binaural [interaural time and level differences (ITD + ILD); blue solid lines] and monaural (contra only; purple dotted lines) conditions. In the monaural condition, sound was only presented to the contralateral ear. Broken black lines indicate spontaneous rate. Normalized mutual information (MInorm) of each ITD + ILD curve indicated by bold blue no. adjacent to curve. Effect size of Wald tests for differences between ITD + ILD and contra-only curves are listed to the right of each panel. *P < 0.01. Unit ID indicated in top left corner of each plot. E: histograms of MInorm for azimuth tuning curves (ITD + ILD) of neurons from normal-hearing (NH, top; N = 41) and HL (bottom; N = 38) rabbits measured at near-threshold level. Only neurons with tuning curves significantly different from spontaneous rate were included (i.e., above threshold; P < 0.01, Wald tests with correction for multiple comparisons). Stacked light and dark blue bins represent curves that were and were not significantly different from contra-only curves, respectively (i.e., binaural and monaural sensitivity, respectively; P < 0.01, Wald tests with correction for multiple comparisons). Broken green lines indicate medians computed only for neurons with binaural sensitivity. ns, No statistical significance (P > 0.05, Wilcoxon rank-sum test).