Boo sound effect

Loud, close, and stopped dead. The hard front edge is what makes someone jump, so this is the take that actually does the job a jump scare needs.

Breathy and unvoiced, right against the microphone. Quieter than the shout and considerably more unsettling, because the closeness is the threat.

Light and singsong, the version an adult uses on a child. It reads as a game rather than a fright, which is what a comedy cut usually wants.

A full room disapproving at once, rolling rather than in unison. The uneven timing is what stops it sounding like one take copied six times.

One voice from somewhere in the room. A lone boo is far more pointed than a crowd, because the audience knows exactly who it came from.

The crowd starting on one note and breaking up into scattered shouts. The change of state is what a single sustained boo cannot carry.