Elevator chimes have been used in passenger lifts since the mid twentieth century to alert waiting passengers that a car has arrived, especially for people who cannot see the indicator lights. The single ding for up and double ding for down became a standard convention in hotels and office buildings. Online, the isolated recording spread as a stock sound effect for videos, games and animations needing a believable building interior. Its clarity and short length keep it popular for edits, interfaces and pranks where an instant sense of place is needed.