The way we perceive the movement of two intersecting discs can be influenced by auditory information. When a brief tone is played at the moment when the discs overlap, people tend to report that the discs bounce off each other instead of streaming past each other. This is known as the auditory-induced bouncing/streaming illusion. In four experiments, we studied how the abruptness of tone onsets and offsets affects the bouncing/streaming illusion. We found that tones with more abrupt onsets and offsets resulted in a higher proportion of bouncing impressions than tones with smoother onsets and offsets (Experiment 1). This effect was not due to differences in volume between the tones (Experiment 2). Additionally, we found that it was the abruptness of the tone onset, rather than the offset, that caused the increase in bouncing impressions (Experiment 3). This effect was observed regardless of the temporal alignment of the tones with the moment of visual overlap (onset-aligned vs. centered vs. offset-aligned; Experiment 4). We discuss these findings in terms of perceptual and decisional explanations of the bouncing/streaming illusion.