Place it at the end of a bathroom joke as the final answer, then follow it with a fart with reverb for a bigger reaction, or a long brain fart when the bit keeps going. Put baby laughing after that only if the group is already laughing, so the run keeps its focus without losing the punchline.
关于此声音
This is a very short, just over one second, spoken clip that repeats the silly phrase poopity poop in a playful, childlike voice. It lands as pure bathroom humour, goofy and deliberately immature, the kind of sound that makes a room laugh because it is so blunt and unexpected. It works best as a quick punchline rather than a longer joke.