The sound comes from The Maze, better known as the Scary Maze Game, a Flash prank that spread online in the mid 2000s. Players were told to guide a dot through a narrow maze in silence, and reaching the third level triggered a flashing image of Regan from The Exorcist paired with this scream. Recordings of friends being tricked helped turn it into an early scream meme, and the clip survived the death of Flash as a standalone sound for pranks and reaction videos.