Binaural processing model based on contralateral inhibition. II. Dependence on spectral parameters

This and two accompanying articles [Breebaart et al., J. Acoust. Soc. Am. 1 10, 1074-1088 (2001); 110, 1105-1117 (2001)] describe a computational model for the signal processing in the binaural auditory system. The model consi sts of several stages of monaural and binaural preprocessing combined with an optimal detector. In the present article the model is tested and validat ed by comparing its predictions with experimental data for binaural discrim ination and masking conditions as a function of the spectral parameters of both masker and signal. For this purpose, the model is used as an artificia l observer in a three-interval, forced-choice adaptive procedure. All model parameters were kept constant for all simulations described in this and th e subsequent article. The effects of the following experimental parameters were investigated: center frequency of both masker and target, bandwidth of masker and target, the interaural phase relations of masker and target, an d the level of the masker. Several phenomena that occur in binaural listeni ng conditions can be accounted for. These include the wider effective binau ral critical bandwidth observed in band-widening NoS pi conditions, the dif ferent masker-level dependence of binaural detection thresholds for narrow- and for wide-band maskers, the unification of III) and ITD sensitivity wit h binaural detection data, and the dependence of binaural thresholds on fre quency. (C) 2001 Acoustical Society of America.