Domofon is the Russian word for the entry intercom fitted in many apartment buildings, where visitors dial a flat number from a street panel and wait for an answer. Recordings of the dialling tones circulate online because the sound is instantly familiar to anyone who has lived with that system. Short clips are shared for edits, skits and reaction videos that need a believable buzzer sound without filming a real panel. Its popularity comes from recognition rather than a single viral moment, and the same tones keep appearing in everyday life.