Figure 1.
Schematic of stimuli and task for the current experiment.
Here, only the 1000-Hz velocity condition is illustrated. The time-change (i.e., duration-judgment) task is shown on the top line, and the pitch-change task is shown on the bottom line. On each trial, a constant-velocity standard glide was presented. Then a variable-velocity comparison stimulus was presented; the comparison velocity took on one of three values. Comparison levels were varied parametrically on the to-be-judged dimension; thus values of the ignored dimension were adjusted in order to maintain the prescribed velocity. For the time-change task, listeners indicated whether the comparison was shorter or longer than the standard. For the pitch-change task, listeners indicated whether the comparison changed more or less in pitch than the standard.
Figure 2.
Proportions of “longer” or “more pitch change” responses as a function of Comparison Level for the time-change (top) and pitch-change (bottom) tasks, and shown separately for the three standard velocity conditions.
Overall, duration tended to be overestimated when the comparison velocity was faster than the standard velocity, and underestimated when the comparison was slower than the standard. On the other hand, pitch change was underestimated when the comparison was relatively fast and overestimated when the comparison was relatively slow. Notably, results were opposite for the time-change and pitch-change tasks.
Figure 3.
Relative PSEs shown separately for the time-change (left) and pitch-change (right) tasks, separately for each standard and comparison velocity condition; comparison velocities are indicated by different color bars.
The plot shows the three-way interaction predicted by the auditory pitch-motion hypothesis.
Table 1.
Values of w derived from the imputed velocity model, shown separately for the time-change and pitch-change tasks, and for the three Standard Velocity conditions.