This sound refers to the famous stabbing-style violin motif from Alfred Hitchcock's Psycho, released in 1960, with music by Bernard Herrmann. Over time, the screech became shorthand for horror across film, TV and internet edits, even for people who have never seen the movie. Online, creators use it as an instantly recognizable cue for danger, paranoia and sudden shock. Its staying power comes from how quickly a single sharp hit can transform an ordinary moment into something tense, eerie or darkly funny.