Detection of unexpected tones in noise: The effect of signal duration

Abstract

The effect of signal duration on the detectability of unexpected tones masked by a continuous wideband noise was assessed using a probe-signal method. This method encourages the listener to attend to a target frequency by presenting the signal most often at that frequency, and only occasionally at other unexpected probe frequencies. The attention contour (percent correct as a function of probe frequency) was considerably broader with 5-ms than with 295-ms signals. However, auditory filter shapes measured using the notched-noise technique were very similar for those two signal durations, indicating that the results obtained in the attention experiments do not simply reflect peripheral frequency selectivity. Further supporting this interpretation, probe tones having the same frequency but a different duration from the target were poorly detected. It is proposed that the subject listens through a time-frequency window whose location and shape in the time-frequency plane is determined by the duration and frequency of the target. [Work supported by the NIDCD and NIH.]