Is acoustic space “learned” in the buildup of the precedence effect?

Abstract

Most of what is known about sound source localization in reverberant environments rests upon knowledge of how the auditory system processes a pair of brief stimuli presented over headphones that simulate a direct sound and a single reflection. In everyday environments, however, sound sources often emit relatively continuous sounds or repeat them often in succession—for example, speech. Also, listeners often move. Dynamic changes in source/listener positions may present a unique opportunity to investigate the effects of “learning” that seem to result in the “buildup of the precedence effect—listeners' ability to effectively localize reverberant sounds after repeated presentation that would be poorly localized after only one presentation. The implicated learning may constitute learning of the spatial acoustics of the environment or learning of the temporal order and timing of reflections (or both). In this study, we sought to disambiguate these two possible learning strategies by comparing listener behavior in response to presentation of repeated pairs of lead/lag noise stimuli presented in a soundfield. Listeners’ perceived sound-source localization and the rate of fusion were measured.