My next door neighbors love it when I run pulsejets on the back deck. Well, one of them thinks they are cool, the other tolerates it out of kindness. I take the 90mm behind our place to the communty centre ballpark thinking that helps, though my buddy up the road pointed out it doesn't matter where I run it, the entire village can hear it - inside.
I think that is the echo between the houses on either side of us.