Those annoying fire alarms gave me the freaks in elementary and JHS. In my first 3 years of grammar school I had no problem with them even though it was a loud kind with a fast rolling beat that was continuous for a few minutes.
In my last 3 years, though in a new school the alarm was more of a series of short, slower-beat siren sounds with pauses (and actually less intimidating than the previous school), I was mellow at first but then I covered my ears a lot, especially when I was informed of a drill, because of the sudden loud sound that bothered me. At least the duck and cover drill bell sounded like the regular recess bell, only a series of ringing for a couple minutes non-stop. The first one I heard, however sounded like a war zone hit.
Middle school had the same bell styles.
In high school we never had fire drills (don't know why, but having a brick building shouldn't be an excuse) but we did have earthquake drills, which were a series of class bell rings. Only once did we have to evacuate for real. My jr. year we had a moderate shaker. Walked to field but it was ust a quick roll call, as administrators were asking the teachers if they had all the students present, and suddenly we were all back in the classrooms or wherever we were supposed to be.
So to make the story short. I too can't stand fire alarms, but the shock is only a quick second, and it only turns to annoying. It stops, it stops, no harm.