Abstract:
The precedence effect refers to the well-known observation that the perceived location of two binaurally presented transient stimuli that are separated by a brief delay depends primarily on the properties of the first arriving sound. In this study, the precedence effect was investigated using 20-(mu)s pulses presented over headphones. Three pulses were presented to each ear simulating a sound coming from directly in front followed by an echo from the side and then from the rear: The first and last binaural pair of pulses were diotic while the middle binaural pair was dichotic with either interaural differences in time or level. A 2AFC lateralization paradigm was used. Highly anomalous lateralization (i.e., lateralization performance near 0%) was observed for many interpulse delays when the total stimulus duration was 2 ms or less. The anomalous results are explained by considering the spectral characteristics of the stimuli.