The phrase is everyday German slang, with Alter used like dude or mate and jetzt hör auf meaning stop it now, which is why the clip travels well even with non German speakers who get the tone instantly. It circulated as a short reaction sound on meme soundboards and in edited videos, where the exasperated delivery does the work without needing context. It stays popular for group chats and gaming moments because it sounds genuinely fed up rather than performed, making it a reusable way to call time on teasing, spam or a bit that has run too long.