A QUANTITATIVE MODEL OF THE EFFECTIVE SIGNAL-PROCESSING IN THE AUDITORY-SYSTEM .2. SIMULATIONS AND MEASUREMENTS

This and the accompanying paper [Dau er nl., J. Acoust. Sec. Am. 99, 3 615-3622 (1996)] describe a quantitative model for signal processing i n the auditory system. The model combines several stages of preprocess ing with a decision device that has the properties of an optimal detec tor. The present paper compares model predictions for a variety of exp erimental conditions with the performance of human observers. Simulate d and psychophysically determined thresholds were estimated with a thr ee-interval forced-choice adaptive procedure. All model parameters wer e kept constant for all simulations discussed in this paper. For froze n-noise maskers, the effects of the following stimulus parameters were examined: signal frequency, signal phase, temporal position and durat ion of the signal within the masker under conditions of simultaneous m asking, masker level, and masker duration under conditions of forward masking, and backward masking. The influence of signal phase and the t emporal position of the signal, including positions at masker onset, w as determined for a random-noise masker and compared with correspondin g results obtained for a frozen noise. The model describes all the exp erimental data with an accuracy of a few dB with the following excepti ons: forward-masked thresholds obtained with brief maskers are too hig h and the change in threshold with a change in signal duration is too small. Both discrepancies have their origin in the adaptation stages i n the preprocessing part of the model. On the basis of the wide range of simulated conditions we conclude that the present model is a succes sful approach to describing the detection process in the human auditor y system. (C) 1996 Acoustical Society of America.