Comparison of the masked thresholds of a simulated moving and stationary auditory signal.

Abstract

The masked thresholds of a simulated moving signal produced by a linear stepwise change in interaural time delay and with movement at two different locations in the phenomenal field were compared with the thresholds obtained with a stationary signal. Using a noise band extending from 75 to 850 cps as the signal and presented against a heterophasic background noise, masked thresholds were made under the following conditions: (1) signal moving at a perceptually slow and fast rates, (2) a perceptually fast moving signal with the signal making four excursions across the phenomenal field during each presentation period, (3) with the signal movement controlled by the observer, and (4) during an extended listening period in which the observer was given no cue as to when the signal was to be presented. The results of the threshold comparisons with these different conditions indicate that the masked threshold of a moving signal is a function only of its localization at any given instant in time and that a moving signal does not elicit a lower masked threshold than a stationary signal.