Place it right after the reveal moment in a short edit, following sudden suspense to set up the payoff and before kids cheering to carry the celebration. It also works after an oh my god wow beat when a second, bigger surprise needs a follow-up.
Über diesen Sound
This is a short vocal reaction lasting about seven and a half seconds, built from three quick, rising ah sounds that break into a drawn-out wow. The delivery is bright and exaggerated, like someone caught off guard by something impressive. It feels playful and full of amused disbelief, the kind of sound that makes a surprising moment land as funny rather than serious.