Domofon systems are the standard entry intercoms in apartment blocks across Russia and Eastern Europe, where a visitor calls a flat from a metal panel at the street door and the resident unlocks it remotely. Short recordings of that buzz and unlock have circulated on Russian soundboards as a recognisable everyday noise. Online, creators use the clip as a punchline for arrivals and fake entries, and it is also paired with other household alerts such as a smoke detector beep in prank edits.