Eaglesnester, Try opening all the windows and sometimes hanging a towel or blanket in front of the window will buffer the shockwave a bit.
Not that I'm condoning discharging a firearm in the city limits, but if I were...I'd move back into the house as far as I could, open all the windows I could and hang dark towels over them. The upside is that the location is hard to pinpoint because the sound is both muffled and re-distributed. The down side is that you can't see anyone approaching if you're shooting out the front door. Almost need a spotter to make it safe. No big deal on the second story however.
Also, the open windows tend to ventilate the gunpowder smell rapidly so the wife doesn't figure things out when she gets home from working all day while we think of ways to shoot at things from within our house.
Liked the hot tub shot! Now that's hunting!