I'm a child of the Cold War, and remember vividly every Monday at noon, they'd sound the CD (that's Civil Defense for the children in the audience) Siren as a test ('This is Only a Test').
I'm REAL glad it wasn't one of these, or it may have blown our home away:
http://autoweek.com/article/car-life/chryslers-cold-warrior I'd be RRREEEAAALLLLL interested in what the on-axis at one meter reading was ! For the life of me, I can not imagine 137db at 100 feet, no wonder you can hear it in a 16 mile area.
And everything goes in cycles. Evidently, Metro Nashville must have qualified for some Homeland Security monies, and they put up something almost as loud a block away from my house. They test it on noon Saturdays, then they also blow it when there are tornado warnings, and it STILL scares the hell out of me. I just wish I could rotate my house so one by one, I could blow the old paint off the other three sides.
J o e y