I suspect the alarm thing harks back to guns that do "go off" (at a similar dB level). I had a smoke alarm that went "off" about 5AM last night and almost resulted in the afore mentioned gun fire.
I couldn't get the thing open to get the failing battery out and it was chirping about every 10 seconds, until I hit it with my 24oz ball peen hammer. The battery came right out after that.
I don't want to sound nasty or anything, but I've lost count of the number of times I've turned up with the Fire Service to a house fire where there are persons trapped only to find the smoke detectors had had the (failing) battery torn out.
This is one thing that really gets my goat, lives have been lost as well as a consequence, it also exposes our fire-fighters to an un-necessary level of risk.
Smoke detectors are installed for a reason.
I'll get off my soap-box now.