Auditory resolution of moving sound sources was determined in a simulated motion paradigm for sources traveling along horizontal, vertical, or oblique orientations in the subjects’s frontal plane. With motion restricted to the horizontal orientation, minimum audible movement angles (MAMA) ranged from about 1.7° at the lowest velocity (1.8°/s) to roughly 10° at the highest velocity (320°/s). With the sound moving along an oblique orientation (rotated 45° relative to the horizontal) MAMAs generally matched those of the horizontal condition. When motion was restricted to the vertical, MAMAs were substantially larger at all velocities (often exceeding 8°). Subsequent tests indicated that MAMAs are a U‐shaped function of velocity, with optimum resolution obtained at about 2°/s for the horizontal (and oblique) and 7–11°/s for the vertical orientation. Additional tests conducted at a fixed velocity of 1.8°/s along oblique orientations of 80° and 87° indicated that even a small deviation from the vertical had a significant impact on MAMAs. A displacement of 10° from the vertical orientation (a slope of 80°) was sufficient to reduce thresholds (obtained at a velocity of 1.8°/s) from about 11° to approximately 2° (a fivefold increase in acuity). These results are in good agreement with our previous study of minimum audible angles long oblique planes [Perrott and Saberi, J. Acoust. Soc. Am. 87, 1728–1731 (1990)]. In summary, the results suggest that: (1) the ability to detect motion is essentially independent of the path traveled by the source, with one noted exception, sources moving within a few degrees of the vertical plane and (2) auditory resolution of sound sources in motion is a U‐shaped function of velocity with resolution degrading as velocities increase or decrease beyond an optical velocity range.

This content is only available via PDF.
You do not currently have access to this content.