If you are seen, enemies may try to call for help. They will activate an Alarm, alerting other enemies. After sounding the Alarm, they will then call for Reinforcements.
To prevent the Alarm from sounding, you can kill enemies as they run for it, or as they are calling for Reinforcements. You can also destroy all the Loudspeakers.
If you reach the Alarm, you can sound the All Clear. Enemies will believe you are dead and stop searching.
You can also convert Loudspeakers into Loud Areas by sabotaging the alarm.
