Put it at the end of a reveal sequence, after the setup clip has finished, so it punctuates the payoff. Follow it with a laugh or a reaction sound to extend the moment, and keep it away from the opening so the surprise still lands first.
关于此声音
This is a short, 1.3-second human vocalisation that stretches a single surprised 'waoah' into a rising, drawn-out sound. It feels startled and amused at once, like someone catching something unexpected mid-sentence and not quite believing it. The delivery is playful and over-the-top, which makes the reaction land as comic disbelief rather than alarm.