People with listening difficulties (LiD) have trouble understanding speech in challenging situations where competing sounds exist, despite having normal audiograms. Among the possible factors involved in LiD, binaural processing plays an important role in sound localization, segregation, and selective attention. In this study, we examined whether the sensitivities to interaural level difference (ILD) and interaural time difference (ITD) are different between the adults with LiD and the controls. Thresholds for discriminating the ILD and ITD were measured with bandpass-filtered noise ranging from 250 to 4000 Hz, using a two-down one-up tracking procedure. The results showed that the ILD threshold was significantly higher in the adults with LiD than the controls (t(10.25) = 2.80, p = 0.018), while there was no significant difference in ITD threshold (t(10.42) = 2.20, p = 0.052). Moreover, there was a significant difference in the variance of ITD and ILD thresholds between the adults with LiD and the controls. Notably, a part of the adults with LiD showed extraordinarily high thresholds for both ILD and ITD tasks (e.g., 2.2 dB and 84.4 μs). These findings suggest that at least a certain type of LiD may be related to the ability to use binaural cues.
Onoe et al. (Wed,) studied this question.