The sound is associated with The Purge film franchise, which began in 2013, where an emergency broadcast siren signals the start of the annual Purge night when all crime is legal for 12 hours. The distinctive rising siren from the films and trailers became a widely shared meme sound online, used far beyond horror content. Creators reuse it for dramatic announcements, pranks, and Halloween edits because the tone is universally understood as a warning, even by viewers who have never seen the movies.