Place it at the start of a disaster clip to signal trouble before the action begins, then follow it with the Danger Alarm Meme Sound for a second warning and the Enemy Spotted Sound Effect when the threat appears on screen.
關於此聲音
This is a rapid electronic warning tone from Half-Life, lasting under half a second and repeating in quick, sharp pulses. It creates a frantic, urgent feeling, like a research facility suddenly going into lockdown after a containment breach. Heard once it signals danger, heard repeatedly it turns a calm scene into comic panic and a moment that demands immediate evacuation.