The article discusses a visual illusion induced by sound, where a single visual flash is perceived as multiple flashes when accompanied by multiple auditory beeps. The study involved flashing a uniform white disk on a black background and varying the number of beeps. Observers consistently reported seeing multiple flashes when the number of beeps exceeded one. The illusion was robust and persisted even when subjects were aware of the actual number of flashes. The temporal properties of the illusion were investigated, showing that it declined at separations greater than 70 milliseconds but occurred within approximately 100 milliseconds of each other. The findings suggest that visual perception can be qualitatively altered by auditory stimuli, indicating a fundamental and widespread property of polysensory mechanisms in the brain.The article discusses a visual illusion induced by sound, where a single visual flash is perceived as multiple flashes when accompanied by multiple auditory beeps. The study involved flashing a uniform white disk on a black background and varying the number of beeps. Observers consistently reported seeing multiple flashes when the number of beeps exceeded one. The illusion was robust and persisted even when subjects were aware of the actual number of flashes. The temporal properties of the illusion were investigated, showing that it declined at separations greater than 70 milliseconds but occurred within approximately 100 milliseconds of each other. The findings suggest that visual perception can be qualitatively altered by auditory stimuli, indicating a fundamental and widespread property of polysensory mechanisms in the brain.