Temporal integration in auditory signal detection

Abstract

The outputs of computer-simulated energy detectors were correlated with the responses of observers in a detection task to determine the duration and shape of the temporal integration process. The 500-Hz 100-msec signal was masked by wideband Gaussian noise. Detectors followed by rectangular and exponential integrators were equally successful in accounting for 70% for the predictable variance in observers' responses. The time constants of the best correlating detector integrators averaged 300 msec for the rectangular and 150 msec for the exponential shaped functions, with single tuned filters of 20- or 40-Hz bandwidth. Energy variations in successive time intervals of 25-msec duration were correlated with responses of observers and energy detectors. A regression analysis which recovered the shape of the energy detector integration functions showed that the observers give significantly negative weight to energy prior to the signal when it is present, but positive weight to such energy when the signal is absent.