Duolingo is a language learning app built around short gamified lessons, daily streaks and its green owl mascot Duo, and its bright notification sounds have become shorthand online for studying and getting something right. Short clips of the app's chimes spread through TikTok, YouTube and meme edits, where creators borrow the familiar correct answer chime to reward a character, mock a study habit or signal that a lesson is finally done. That instant recognition keeps it useful long after the app itself, because viewers hear the sound and immediately understand the joke without any explanation.