I'm just starting and it's so difficult to tell what an alarm is. I'm going through the manufacturing plant and I just passed a room of 4 guys without ever alarming any of them. Right after I walk through the next door there is a red flashing light and an alarm like sound going off. None of the enemies are alerted, though. Is this an alarm that I set off? Or is this just an alarm that the enemies set off an are ignoring now?
Its the part with the tutorial on security systems.