The electric school bell has signaled class changes in schools for decades, so its ringing is instantly recognizable to students everywhere. Online, the isolated bell sound became a popular prank clip, shared on soundboards for playing at the wrong moment during class or in videos. Creators use it to fake dismissals, interrupt streams, or open school-themed skits. Its staying power comes from that built-in reflex: almost everyone who went to school reacts to the bell without thinking.