Place it at the exact frame a learner selects the right note, then follow it with a correct answer sting for quiz edits, or let a background music loop carry the next exercise underneath.
關於此聲音
This clip is a single Fa note, held for under a second, with a clean pitched tone and no voice or backing. It feels calm and precise, like a clear answer in a lesson, giving a small moment of focus rather than a joke or a shock.