Hmm, I remember the classroom I had kindergarten in had a fire alarm installed right inside it. And it was one of those older ones that sound like a buzzer with a red flashing light on the bottom. Ouch! (I'd describe the model number, but I don't want it to get too technical; I can just say it was a Simplex fire alarm system from the 1970s.) Usually the teacher didn't mind me trying to sit away from the alarm signal. She was pretty cool with that.
None of my classes for grades 1-6 had alarms in the rooms, but in some of the classroom pods, it'd still be pretty loud. No visual signals, either.
During middle school, none of the "regular" classrooms had alarms in them, but the CCC lab, wood shop room and music classroom each had an alarm in them. (These were even older fire alarm buzzers from the 1950s!) One time we were in music class and I was right near the fire alarm when it went off. Sheer TORTURE!
My ears probably hurt all day. Of course they'd have at least one alarm in the cafeteria, the auditorium and the gymnasium, but I'm not counting those (in elementary and middle school I'd still try to sit as far away from the alarm as possible in lunch.)
High school was trickier. None of the "regular" classrooms had fire alarms in them, but they had tons in the hallways, FOUR in each of the main building's four cateterias (it holds 4,000 students) and I recall the media centers having an alarm in them, and these rooms weren't that large! Of course in the classrooms, if there was an alarm right outside the room, I'd try to sit as far away from the doorway as possible. It didn't help that high school had the LOUDEST fire alarms in the entire city of Brockton! (Again, they were buzzers, installed when the school was first built in 1969, and they haven't since been replaced!! !)
College was different. By then, my anxiety about fire alarms had lowered a little, but on the rare occasion we'd be in a classroom with an alarm in it (some of my drama classes were in a room that had an alarm signal right at the front of the room; this time it was one of those newer electronic ones that make the shrill screech, like a bunch of smoke alarms going off, accompanied by a REAL strobe) I would still resist sitting pretty close to it. Again, the teachers wouldn't mind. We also didn't have routine fire drills here, and the rare time there would be a false alarm, it would be an accident (I only recall the Technology building having one in spring 2008, caused by someone bumping into a pull station!)