The precedence effect: Spectral, temporal, and intensitive interactions

Within the phenomenon termed the precedence effect, location dominance of the leading signal has been associated with the time-course of spatial cues, with stimulus onset playing a dominant role. For a continuous stimulus consisting of lead and lag components, each with different interaural delays, a pattern of interaural level differences and interaural time delays will be created that varies in a specific manner as a function of frequency. In principle, provided that a sufficiently large spectral interval is available, this type of frequency dependence allows one to infer the direction of the leading sound source. We investigated precedence using such lead-lag stimuli and asked listeners to judge the lateral position(s) of the stimuli, depending on spectral content. Results suggest that with such stimuli, lateralization is dominated by interaural cues available within and across auditory filters. In addition, the data suggest there exists a ‘lateralization bias’ that depends on the patterning of interaural cues that exist across frequency.