Uncertain Signal Detection with Simultaneous Contralateral Cues

Abstract

A series of auditory signal-detection experiments was run under conditions of signal-parameter uncertainty. This uncertainty was effected by allowing one signal parameter, either signal frequency or starting time, to vary randomly across the sequence of experimental trials. These experiments, runmonaurally, employed a simple yes-no detection procedure, signal plus noise occurring on half of the trials and noise alone occurring on the other half. A series of comparison experiments using the same observers was run under identical conditions, with the addition of a simultaneous cue signal in the contralateral ear. This cue was present on both signal and no-signal trials and was identical, in all parameters except amplitude, to the signal that might have been presented to the detecting ear. The results demonstrated that a simultaneous contralateral cue degrades performance at relatively high signal-to-noise levels, and that at low signal levels such a cue facilitates performance of the detection task. The resulting psychometric functions suggest an interpretation in terms of a crossmasking and uncertainty-reduction hypothesis.