Referee whistles have signaled fouls, kickoffs and full time in football since the 1870s, when Joseph Hudson created the pea whistle in Birmingham, and the piercing blast is now universal across sports. Online, the isolated whistle became a staple of sports fail compilations and meme edits, where a single tweet marks a blunder the way a referee flags a foul. It spread through royalty-free sound effect libraries and reaction soundboards, and it still works because everyone instantly understands the language of the whistle: stop, pay attention, something just went wrong.