Domofon is the generic Russian word for the entryphone systems installed in most post Soviet apartment buildings, where visitors press a flat number outside and wait for a resident to answer and unlock the door remotely. Recordings of the ringing, beeping and unlocking tones have circulated on Russian speaking social media and soundboards for years as a nostalgic everyday sound. Online creators reuse it far beyond Russia because the buzzer instantly signals an apartment block entrance, even for viewers who have never used the system themselves.