*****
When I was a kid living at Ft Lewis, we got sonic booms several times a day from fighters taking off from McChord AFB. It got to the point that we didn't even notice them.
My grandparents came up to visit one time and the first time they heard one, they freaked the fuck out. One second they're sitting there talking with my parents and the next they're crawling around on the floor looking all distressed and shit, and we're sitting in our chairs looking at them and wondering what their problem was.