Abstract:
Previously, it was reported that differential auditory thresholds for velocity and acceleration do not appear simply related to thresholds for displacement using synthesized sound sources [Wang and Lutfi, J. Acoust. Soc. Am. 95, 2897(A) (1994)]. The present study was undertaken to de-termine if the failure to find a simple relation might be due to differences in the types of cues mediating these thresholds. The sound of a source moving in a straight path on the azimuthal plane was synthesized over headphones to include three dynamic cues for motion: Doppler shift, intensity, and interaural delay. The three cues were perturbed slightly from trial to trial so that correlations with listener responses could be used to estimate the relative weight given to each cue. A 2IFC procedure was used to measure differential thresholds for displacement, velocity, and acceleration of four listeners. For the discrimination of displacement, responses were most highly correlated with intensity or interaural delay, but for the discrimination of velocity and acceleration, responses were most highly correlated with Doppler shift. The results provide a means of accounting for differences in sensitivity to motion that cannot be inferred from sensitivity to displacement alone. [Research supported by NIDCD R01 DC01262-04.]