Put it at the very start of a clip, before any spoken line, then follow it with Enemy Spotted to signal a test beginning or Okay Let's Go to start the challenge.
इस साउंड के बारे में
This is a very short single electronic beep from Portal 2, lasting under a fifth of a second, used to open a monologue by the game's Announcer. It feels crisp, official and slightly ominous, like a facility system clearing its throat before an important instruction. The tone comes from the Aperture Science announcements in the game, where it signals that a message is about to begin.