The chime belongs to Sydney Trains, the suburban rail operator serving Sydney in New South Wales, Australia, where the tone is heard daily before automated and live information announcements. Transport enthusiasts and trainspotters recorded platform audio for years, and short clips later circulated on soundboards and in travel edits. Because so many residents and visitors associate the two notes with arriving trains and platform updates, creators now use it as shorthand for Sydney public transport, even in parody announcements far from an actual station.