Lateralization and detection of low-frequency binaural stimuli: Effects of distribution of internal delay

The position-variable model @R. M. Stern, Jr., and H. S. Colburn, J. Acoust. Soc. Am. 64, 127–140 ~1978!#, which had been developed to describe binaural phenomena at 500 Hz, is extended to describe and predict binaural lateralization and detection phenomena at frequencies of 250–1200 Hz. The major modification made to the model is the use of a frequency-dependent form of the function that describes the relative number of binaural coincidence detectors in the model as a function of their internal delay. This function is fitted to describe the lateralization of pure tones with a fixed ITD over a range of frequencies, and the ratio of N0Sp to NpS0 binaural detection thresholds. The extended model describes without further modification the general dependence of the lateral position of pure tones on ITD and frequency, the lateralization of amplitude-modulated tones, and the ‘‘dominant region’’ lateralization phenomenon. © 1996 Acoustical Society of America.