Lack of a clear head movement benefit in a spatial release form masking task

Abstract

The study of spatial benefit in complex listening environments often requires listeners to maintain a fixed head position so that controls are in place for understanding binaural function. In natural listening environments, however, listeners may use head movements (e.g., turns and tilts) to achieve their maximum speech reception. In a previous study, we developed a spatial release from masking task that adapts the location of the maskers to determine the angular threshold for a predetermined masking release (in dB), and in the present study, we modified this task to allow for the listeners to move their heads as they wished to maximize performance on the task. Twenty young normal hearing listeners were tested on the head-fixed and head-free conditions. Head tracking was collected for posthoc analyses. Overall, there was no significant difference in behavioral thresholds between conditions despite wide ranges of head movements in the head-free condition. Interestingly, large individual differences in head movement translated to a narrowing of the variance in behavioral thresholds relative to the head-fixed condition, suggesting that listeners were indeed optimizing their speech reception. Further analyses will dissect the types of head movements and strategic differences among the participants, with implications for listeners with hearing loss.