This sound is associated with Raul Gil, a well-known Brazilian television presenter, and it spread online as a reaction clip beyond its TV context. In meme culture, “xiii” became a fast shorthand for embarrassment, doubt or the feeling that someone just messed up in public. It remains popular because the delivery is short, expressive and instantly understood by Portuguese-speaking audiences, especially in edits, reposts and chat-style videos where a tiny reaction sound can carry the whole punchline.