The chirp comes from the world of Cisco desk phones, the IP handsets found in many offices, call centres and workplaces around the world. Because those phones are so common, their short alert tone is instantly recognisable to anyone who has worked near one. Online, creators have lifted that familiar workplace sound for short videos, streams and memes, using it as a quick shorthand for a call, a notification or an interruption. Its simplicity and realism keep it useful long after the original office context.