The relative salience of auditory motion cues was measured in a series
of four experiments. In the first three experiments, all combinations
of three different auditory motion cues (intensity changes, Doppler
frequency shifts and interaural time delays) were presented at various
source trajectories, parallel to the listener's frontal plane. In the
first experiment, the velocity of the source was varied from 7.5 to
100 miles per hour and the point of closest passing was varied from 1
to 100 meters. In the second experiment, the angular position of the
source always moved from minus 30 degrees to plus 30 degrees and the
minimal distance of the path was varied. In the third experiment,
the simulated velocity was fixed at 33 miles per hour for all stimuli.
The results of these experiments show that monaural acoustic cues of
intensity and Doppler frequency changes had the greatest effect on the
listeners' judgments of perceived velocity. The binaural cue of
interaural time delays had little effect on the velocity judgments.
The results also show that the distance traveled by the source was
found to be a more salient velocity cue than actual sound source
velocity.
