Audience laughter has been a staple of television comedy since the early days of studio sitcoms, when producers added recorded crowd reactions to signal jokes and keep the energy of a live taping. As short-form video and memes grew, that familiar track was lifted from its television context and reused as a standalone reaction sound, a quick way to tell viewers something was supposed to be funny without any explanation. It survives because it is instantly understood across languages and formats, from reaction videos and pranks to gaming clips and classroom presentations.