Place this knock early in a scene to signal an arrival, then follow it with FBI Open Up for a raid joke, or save the FNAF jumpscare scream for a horror payoff right after the door opens in the edit.
About this sound
This clip is a short recorded knock against a solid wall, a series of dull thuds made by knuckles on a hard surface. It feels tense and attention grabbing, like an unexpected visitor or a warning from the next room, which makes listeners pause and listen for who might be there.