Advised by Dr. Lily Wang and Dr. Ellen Peng (Boys Town National Research Hospital)

Spatial hearing provides access to auditory spatial cues that promote speech perception in noisy listening situations. However, reverberation degrades auditory spatial cues and limits listeners’ ability to utilize these cues for segregating target speech from competing babble. Hence, spatial unmasking—an intelligibility benefit from a spatial separation between a target and masker—is reduced in reverberant environments as compared to free field. This work tests the hypothesis that interaural decorrelation, the result of increasing reverberation, will broaden the perceived auditory source width with a cascading effect of reduced auditory spatial acuity and subsequently poorer spatial unmasking. To understand the perceptual consequences of poorer spatial unmasking in reverberation, four tasks relating to functional spatial hearing were assessed in virtual reverberant environments: interaural coherence discrimination, perceived auditory source width, auditory spatial acuity, and spatial unmasking. Three primary auditory environments were simulated using ODEON and auralized to vary interaural coherence: a control anechoic environment, a classroom designed to meet classroom acoustics standards, and a classroom of the same size with more severe reverberation. Individually measured head-related transfer functions were used to binaurally reproduce the auralized signals over headphones to a group of normal-hearing adults. The results indicate that increasing reverberation correlates to increased ASW perception and decreased performance in IC discrimination, auditory spatial acuity, and spatial unmasking.