Using cognitive measures to understand individual differences in spatial release from masking beyond those explained by perceived spatial separation

Spatial release from speech masking (SRM) refers to improved speech recognition when speech maskers are perceived to be separated from target locations. Binaural manipulations, such as conflicting interaural time and level differences, have been shown to reduce SRM and perceived lateral position. We assessed the impact of perceived target-masker separation by measuring spatial judgments of binaurally manipulated speech and correlating those judgments to individual listeners’ SRM scores. The results account for 2.5–4 dB of SRM across the measured lateralization range. Individual SRM scores, however, spanned a range of more than 10–12 dB, suggesting that other factors primarily account for variation in speech unmasking. Past studies suggest that differences in working memory and attention could be responsible. Here, we relate variation in SRM and spatial perception to variation in working memory as assessed by an auditory running digit span task and selective attention as assessed by the Stroop Squared, Simon Squared, and Flanker Squared tasks. Results suggest the importance of considering non-acoustic aspects of listening ability, which may limit access to benefits of spatial hearing. [Work supported by NIH R01-DC016643.]