It's hard to say .. You may not have 'noticed' him grow because you see him everyday. Measuring growth with a static measuring device is sometimes the only way to actually detect it.
Maybe at one point but I think people are so used to hearing them go off now that no one really notices, maybe not even care anymore.
Not where I am from. I have never seen anyone other than the owner of t.he car rush to the car when the alarms go off. Most people just complain about the noise