The tone comes from the Earthquake Early Warning system operated by the Japan Meteorological Agency, launched nationwide in 2007 to give seconds of warning before strong shaking arrives. Broadcasters, especially NHK, play the chime on television and radio, and mobile phones across Japan carry a similar alert. Outside Japan the recording spread through news footage of major quakes, YouTube compilations and social media edits. Because so many viewers now recognise it instantly, creators borrow it worldwide as shorthand for an incoming disaster, emergency announcement or moment of panic.