The telephone hang-up sound comes from the real-world action of ending a landline call by putting the receiver back on the cradle. Variations of this effect have been used for decades in radio, film, television, and online edits to signal an abrupt end to a conversation. It remains popular because the meaning is instantly clear, even to viewers who have never used older phones. In memes and short videos, creators use it as a quick audio cue for rejection, annoyance, or comedic finality.