The effect of timing and spatial separation on the velocity of auditory apparent motion

Abstract

Previously, it was shown that the minimum conditions for the illusion of auditory apparent motion (AAM) depend on stimulus timing hut not spatial separation. In the present experiment, the effects of stimulus timing and source separation on the perceived velocity of AAM were examined. Eight listeners estimated the velocity, duration, and distance traveled of AAM, using a no-modulus, magnitude estimation procedure. Four burst durations (25, 50,100, and 300 msec), 10stimulus onset asynchronies (SOAs; 30, 40, 50, 60, 70,80, 90, 100,110, and 120msec) and two separations (10°and 40°)were tested. Perceived velocity estimates were related to the total duration (burst duration + SOA) ofthe stimulus sequence. The effect of separation on velocity was extremely small but statistically significant. These results are similar to those obtained previously on the minimum conditions for AAM. Duration estimates were related only to total duration, but separation estimates were related to both separation and total duration. These results suggest that velocity is possibly a primary dimension of AAM that is independent of source separation.

Velocity discrimination of auditory image moving in vertical plane

“…This result agrees with the data reported by Strybel et al (1998), where authors estimated the duration and separation between the sources to determine whether the velocity of AAM could be predicted from these estimates. It was found that the perception of velocity of apparent motion was mainly affected by stimulus timing.…”

“…It was found that the perception of velocity of apparent motion was mainly affected by stimulus timing. Physical separation also affected perceived velocity, but the effect was small (Strybel et al, 1998).…”

Auditory Spatial Perception: Auditory Localization

“…An argument for the snapshot theory is that a sound source does not need to actually move to create the sensation of movement. The proper timing of two acoustic stimuli produced from two separate sound sources can produce the sensation of sound source motion called auditory apparent motion (AAM) (Strybel et al, 1998). Stimulus timing is determined from the durations of both stimuli and the difference in their onset times, called stimulus onset asynchrony (SOA).…”

“…Stimulus timing is determined from the durations of both stimuli and the difference in their onset times, called stimulus onset asynchrony (SOA). The spatial separation between the two sound sources does not affect the strength of the AAM sensation and only affects the perceived velocity of motion (Perrott and Strybel, 1977;Strybel et al, 1998). For example, Strybel et al (1990) reported that two sound bursts with durations of 50 ms and a SOA of 40-60 ms can produce an AAM with sound sources separated by as little as 6° or as much as 160°.…”

The generation of vibrotactile patterns on a linear array: Influences of body site, time, and presentation mode

“…On the other hand, if the velocity is too great, a compression in overall extent may be perceived (Whitsel et aI., 1986), and minute changes in length of static patterns are readily detected (see, e.g., Schneider, Hughes, Epstein, & Bach-yRita, 1986). The influence of velocity on judgments of apparent motion can be substantial (Strybel, Span, & Witty, 1998) and will be discussed later. Furthermore, directional acuity, a gauge of the resolving power of the sensory system, is an additional factor that may vary with presentation parameters over body sites (Costanzo & Gardner, 1980;Essick, 1991;Gardner & Palmer, 1990;Gardner & Sklar, 1994) and is important in sequential pattern processing.…”