Spatial release from masking and pupillometry

Speech perception in complex listening environments is driven by both the auditory factors and the cognitive abilities. There are various ways in which cognitive processing while perceiving speech could be measured. In the present study, we applied pupillometry to assess cognitive processing load resulting due to various demands imposed by the presented speech. PupilCore eye glasses were used to capture pupil dilation while doing two tasks: 1. Speech recognition task when the target and the maskers were either colocated or spatially separated, and 2. a localization task where the listeners had to discriminate whether the two sounds originated form the same location or different locations. Initial data analysis revealed different patterns of pupil dilations for the collocated and spatially separated conditions. For the collocated condition, the listeneing effort had a u-shaped pattern as the target-to-masker increased whereas the listening effort linearly increased as the target-to-masker ration increased for the spatially separated condition. Also, the pupil dilation decreased as the localization task became easier. The intricate relationship between listening effort and listening environment will be discussed in detail.