Biological motion is perceived as faster with shorter auditory time intervals.

Perceptual experience is continuously refined by crossmodal interactions in time. Prior research shows that auditory timing can modulate the perceived speed of visual motion with simple stimuli (e.g., flashes, clicks). It remains unknown whether such temporal interactions extend to complex, socially meaningful motion, where timing carries biological significance. Here, we investigated whether auditory timing affects the perceived speed of human locomotion depicted by point-light walkers (PLWs). Across experiments, participants compared the walking speed of sequentially presented, visually identical PLWs accompanied by footstep sounds differing only in inter-sound interval. Perceived walking speed systematically rescaled with auditory timing, revealing a robust crossmodal temporal influence. To assess whether this effect relied on specific temporal anchors, we manipulated either the onset or offset of footstep timing. The crossmodal influence was not locked to onset or offset cues, indicating that overall auditory time intervals shape visual motion perception rather than acting at discrete moments of audiovisual alignment. Moreover, the effect persisted across semantically congruent and incongruent sounds, suggesting that auditory timing primarily governs perceptual alignment across modalities. Together, these findings indicate that audiovisual interactions in time extend to naturalistic biological motion. Auditory timing provides a dominant low-level cue supporting perceptual coherence in dynamic multisensory environments.