The boxing bell comes from real ringside tradition, where a metal bell at the judges table marked the start and finish of each round long before electronic timers. Its clear clang became shorthand in films, cartoons, games and sports broadcasts for any contest beginning or ending. Online, creators borrowed that cue for edits far beyond boxing, using it for rap battles, gaming duels, classroom challenges and comedic knockouts, because the sound alone explains the stakes in under a second.