Place it right before the ambush or pick in your edit, then follow the fallout with an enemy spotted cue for the reveal. For a failed objective attempt, let this play first and save the heavier alert sounds for when the fight actually breaks out.
Über diesen Sound
This is the short 1.2-second Need Vision ping alert from the in-game communication wheel, a sharp electronic chirp used to request wards. It feels urgent and a little nagging, like a teammate tapping your shoulder because the river or jungle is completely dark and unsafe to enter blind.