Domofon is the Russian word for an apartment intercom system, and short recordings of its buzz have circulated on soundboards as everyday, instantly recognisable effects. The third variant in this set offers a clean, short version that editors keep reusing for doors, entrances and interruptions. Online, it spread through meme edits, short prank clips and reaction videos where a familiar household noise is funnier than a dramatic doorbell. It remains popular because it needs no explanation, works in almost any language, and signals that someone unexpected has just arrived.