Booing is a familiar audience reaction, used for generations to signal disapproval when a performance, opinion or result disappoints. Short versions of that reaction have become popular online as quick reaction sounds, because they communicate rejection without needing any explanation. Creators drop them into memes, streams and short videos to punctuate a failure or an unpopular take, and listeners recognise the meaning immediately even outside its original context. Its staying power comes from that simplicity: one brief, universal sound that turns disappointment into a joke.