The presence of a stranger near my front, or patio door, at night? Sounds like a 911 call, then a couple of alarm siren tweak's! That is loud.
Would not be too hard to kick my front door in, my first sight of your head coming up the stairs? Would have my TruGlo sights superimposed on it.
The Police announce their Office, and reason to be in a premises, very loudly, and a lot! So no mistakes in that case.