The role of high-frequency cues for spatial hearing in rooms

Abstract

The ability to attend to a sound source of interest while ignoring competing sounds is vital to navigating everyday acoustic scenes. Commonly, this ability depends on the ability to focus on a sound source using acoustic spatial cues, particularly interaural time differences (ITDs) and interaural level differences (ILDs). Based on past studies of localization in anechoic settings, low-frequency ITDs have been thought to dominate perception of source location. However, reverberant environments differentially degrade ITDs and ILDs, which may affect their relative influence on localization. Moreover, a recent study suggests that ILDs play a bigger role on spatial perception in reverberant settings than in anechoic settings. Here, in a series of localization and spatial attention experiments using high-pass, low-pass and broadband sounds, we tested the hypotesis tat high-frequency ILD and envelope ITD cues are important for spatial judgments in reverberant rooms. We also measured the brainstem frequency following responses (FFRs) of individual subjects in response to click trains and spoken syllables. Results suggest that compared to in anechoic space, in reverberant settings, high-frequency cues are more reliable and influential on perception and that the strength of FFR phase locking to stimulus envelope predicts how well individual listeners can direct spatial attention. © 2013 Acoustical Society of America.