The doorbell chime is one of the oldest household alert sounds, based on electric bells and later electronic two-tone ding dong units fitted in homes around the world. As a stock sound effect it spread through film, television and online video libraries, where editors reused it whenever a scene needed an arrival without showing the door. On soundboards and in short videos it became a simple prank and storytelling shortcut, also paired with a door knocking sound effect for a longer entrance sequence.