This is a real-world transit recording from Hong Kong's Mass Transit Railway, rather than a clip from a film, show or meme. The MTR door chime is heard daily by millions of commuters as trains prepare to leave stations across the city, which is why the sound feels so familiar even to people who have only visited Hong Kong once. Online, short train and station recordings are commonly shared as practical sound effects for travel videos, animations and city montages, where an authentic door sound adds place and movement without needing any explanation.