Human Sensitivity to Minimal Auditory Temporal Irregularities

Abstract

The objective of the present study was to characterize the temporal processing abilities of healthy adults using a modified jitter paradigm in which only a single click in 25-click train stimuli had been displaced. It was hypothesized that thresholds would be higher than those observed for wholly jittered stimuli. It was also expected that the data would support the ‘dual mechanism hypothesis’, i.e., that the auditory perceptual system employs different strategies across different ranges of inter-click intervals (ICIs) to detect irregularities. Using 48 stimulus conditions (four jitter types, two masking conditions, six ICIs), it was hypothesized that performance would be superior on tasks with two aberrant ICIs compared to one. Fifteen subjects were tested, and repeated measures ANOVAs were performed to assess the significance of the perceptual effects observed. The data were supportive of all stated hypotheses. They provide a greater understanding of how the auditory system detects temporal irregularities.