Hearing and vision are integrated continuously: the brain binds a voice to moving lips, a thump to the ball hitting the floor, provided they land inside a temporal window of very roughly a hundred milliseconds. Inside the window, vision can even drag sound’s apparent location, which is why cinema speakers can sit beside the screen while dialogue seems to come from mouths.
Illusions mark the seams. The McGurk effect shows vision editing what is heard; the double-flash illusion shows audio editing what is seen.
Live visuals sit entirely inside this machinery. Reactivity reads as connection only when latency stays within the binding window, which is why frame-late visuals feel dead even to audiences who cannot say what is wrong.