This sound comes from the State Anthem of the Soviet Union, one of the most recognisable national anthems of the 20th century. Online, short excerpts became a long-running meme in image macros, video edits and gaming clips, usually to signal a Soviet, communist or Russia-adjacent joke. Its spread owes a lot to the anthem's instantly dramatic opening and the way it creates an exaggerated sense of seriousness in just a few seconds. That combination keeps it popular in ironic meme culture.