Train horns have long been used as warning signals on railways, and recordings of them have become a familiar staple of online soundboards and video editing. The deep, unmistakable blast is instantly associated with trains, travel and arrival, which makes it easy for viewers to understand without explanation. Creators use it in memes, pranks, reaction videos and gaming clips to signal danger, interrupt a moment or mark a dramatic entrance. Its popularity endures because it is loud, simple and universally recognised, working across languages and cultures in short-form video.