This sound comes from Lionel Richie's song "Hello," released in 1984. The opening lyric became one of the most quoted lines from the track and spread far beyond the original song through reaction clips, parody videos and short-form memes. Online, people use it as a dramatic greeting, a playful way to start a message joke, or a cue for surprise recognition. Its staying power comes from how quickly the line is recognised, even by listeners who only know that one moment.