A TEST OF AN INTERRUPTION TEMPORAL-UNCERTAINTY THEORY OF AUDITORY BACKWARD RECOGNITION MASKING OF TARGET DURATION

The present study examined auditory backward masking in a task requiri ng subjects to label a target sound as having a long or short duration . Perception of target duration was influenced by the interaction of t he effects of (1) the similarity of the target/mask duration, (2) the acoustic similarity of the target and mask (tone vs. white noise), and (3) the interstimulus interval (ISI) between the target and mask. Spe cifically, relative to the long duration (100 ms) mask, the short dura tion (40 ms) mask helped performance for the target having a similar s hort duration (55 ms) but hurt performance for the target having a dis similar long duration (85 ms). This effect of the similarity of target /mask duration was greater for acoustically similar targets and masks than for acoustically dissimilar targets and masks, and particularly s o at the intermediate (45, 105, 165, 205 ms) ISIs. These results can b e explained within the framework of Massaro and Idson's (1976) two-sta ge model by assuming that masking of perceived auditory duration is th e result of two processes: (a) the mask's interruption of target proce ssing in a peripheral auditory processing stage, and (b) a confusion o f which item is the target vs. the mask, due to temporal uncertainty i n the transfer of the target and mask into a central auditory processi ng stage.