Door opening sounds are among the most reused everyday effects in online video because almost every story needs someone to enter, leave, or discover a room. This clip, titled in Chinese as kai men, simply means opening a door, and it circulates as a short, clean utility sound rather than a clip from a film or meme. Editors reuse it across gaming videos, skits, and reaction edits, often paired with a door knocking sound effect to complete the entrance before dialogue begins.