Tuning in the time domain revealed through detection of auditory signals of unexpected duration or presentation time

Abstract

Bert Scharf was interested in how expectation affects auditory performance. He explored this question using the probe-signal method of Greenberg and Larkin, in which the listener is led to expect a particular stimulus but is occasionally presented with an unexpected but equally detectable one. The detectability of unexpected stimuli provides insight into the listener’s template for the expected stimulus. Bert’s expectation research, which focused on the frequency domain, inspired us to extend the inquiry to the time domain. We have seen that signal detection can be quite poor for signals of unexpected duration as well as for signals presented at unexpected times, indicating that listeners attend selectively to these two temporal aspects of sound. However, this temporal tuning is much broader for starting time (hundreds of milliseconds) than for signal duration (can be <25 ms). Thus, it appears that listeners can select the template for signal detection with considerable accuracy, but do not apply the selected template strictly to the expected starting time of the signal. We are grateful to Bert for his mentorship and keen interest in this topic. [Work supported by NIH/NIDCD.]