Detection of static and dynamic changes in interaural correlation

This study examines the relation between a static and a dynamic measure of interaural correlation discrimination: (1) the just noticeable difference (JND) in interaural correlation and (2) the minimum detectable duration of a fixed interaural correlation change embedded within a single noise-burst of a given reference correlation. For the first task, JNDs were obtained from reference interaural 'correlations of + 1, - 1, and from 0 interaural correlation in either the positive or negative direction. For the dynamic task, duration thresholds were obtained for a brief target noise of + 1, - 1, and 0 interaural correlation embedded in reference marker noise of + 1, - 1, and 0 interaural correlation. Performance with a reference interaural correlation of + I was significantly better than with a reference correlation of - 1. Similarly, when the reference noise was interaurally uncorrelated, discrimination was significantly better for a target correlation change towards + I than towards - 1. Thus, for both static and dynamic tasks, interaural correlation discrimination in the positive range was significantly better than in the negative range. Using the two measures, the length of a binaural temporal window was estimated. Its equivalent rectangular duration (ERD) was approximately 86 ms and independent of the interaural correlation configuration. (C) 2002 Acoustical Society of America.