Place it at the very start of a Portal-themed edit to mark the scene change, then follow it with Click Nice to confirm the moment and a Pop Sound Effect to punctuate the reveal.
关于此声音
This is a very short electronic beep, lasting less than a quarter of a second, taken from the start of a spoken line in Portal 2. It has a clean, clipped tone that feels abrupt and alert, like a system waking up before an announcement. It comes from the game's dialogue introduction, associated with GLaDOS or the facility announcer.