Bomb beeping is a classic countdown trope borrowed from film and television, where a steady electronic beep signals that a device is armed and time is almost up. Online, the short clip has become a handy shorthand for that same feeling, even when no bomb is involved. Creators on short-form video and soundboard sites search for it as bomb beeping and drop it into pranks, challenges and reaction edits to make a wait feel urgent. Its simplicity is why it lasts: a single repeating tone instantly tells an audience that something is about to happen.