In visual competition, the perception of ambiguous visual patterns changes spontaneously. Although the process causing this perceptual alternation remains unclear, recent evidence suggests various types of non-visual influences in resolving visual ambiguity. In the present study, we investigated cross-modal modulation of a transient stimulus on visual perceptual stability (i.e., alternation frequency). Participants observed an ambiguous visual figure and reported their perceptual alternations. Concurrently, we presented visual and auditory transient events. The results revealed that the auditory as well as visual transient events destabilize the current perception (i.e., they increase alternation frequency) around 0.5-1.5 s after the event. In addition, the magnitudes of auditory and visual effects were comparable and positively correlated within participants. These results suggest that the visual perceptual stability can be under the influence of processes that are shared by different senses.