The sound comes from the Junkers Ju 87 Stuka, the German dive bomber used early in World War II. Its Jericho Trumpet sirens, driven by the wind during a dive, were designed for psychological effect as much as warning. Newsreels, war films and later cartoons reused the screaming dive so often that it became the stock sound for anything plummeting from the sky. Video games, memes and edits still borrow it because audiences recognise the falling terror instantly, even when the object on screen is not a plane at all.