The Role of Consistency of Interaural Timing Over Frequency in Binaural Lateralization

ABSTRACT Recent experimental results indicate that consistency of interaural timing information plays an important role in the lateralization of broadband binaural stimuli. Specifically, it appears that the binaural system lateralizes stimuli from the centroidsof their cross-correlation functions after peripheral bandpass filtering, and it weights more heavily the contributions of peaks in these functions that occur at internal delays that are consistent over a range of frequencies. In this paper we extend the position-variable model to incorporate a mechanism that effects this weighting, which we refer to as straightness weighting. Straightness weighting is introduced by assuming a second stage of processing which records coincidences of activity from outputs of primary coincidence-counting units with the same characteristic internal delay, but with different characteristic frequencies. We demonstrate that the extended position-variable model can describe the role that straightness plays in the lateralization of bandpass-noise stimuli.