Binaural detection as a joint function of masker bandwidth, masker interaural correlation, and interaural time delay: Empirical data and modeling.

Empirical data are reported demonstrating how binaural detection is affected by joint variation of masker bandwidth, masker interaural correlation, and interaural time delay (ITD) of both masker and tonal signal. Most of the data were obtained with stimuli centered at 500 Hz; supplemental measures were obtained with stimuli centered at 4 kHz. The results indicate that as the interaural correlation of the masker (ρ) is decreased there is (1) an overall increase in threshold signal-to-noise ratio (S/N) and (2) a progressively smaller effect on threshold S/N as ITD is increased. All of the data were accounted for quite accurately using the same quantitative, interaural cross-correlation-based model that was recently shown to account for binaural detection and discrimination data obtained in previous experiments. Importantly, the new data were predicted and explained using values of model parameters that were identical or very close to those found to predict accurately the earlier data. The success of the enterprise attests to the robustness of the approach and the generality of the model's ability to make accurate predictions of binaural performance over a wide range of historically important stimulus conditions.