This type of sound comes from the long TV tradition of laugh tracks and studio audience reactions used in sitcoms. Rather than pointing to one single source, online creators use short laughter clips like this to recreate the feel of classic television comedy. It spread in memes, YouTube edits, and short-form videos because the joke reads instantly: the sound tells viewers a line is supposed to be funny. It is still popular because it adds familiar comic timing in only a few seconds, much like clapping or a fail sting.