I put weather stripping around the garage door. 2 benefits: greatly reduced noise from my power tools and keeps out wind blown rain. I can turn on the DC and planer and can barely hear a thing when standing outside the garage. If it's hot, I have to open things up, so I'm thinking of installing a wall unit A/C.
My nearest neighbor's house is 12' away and she has never complained about the noise (and she is a b*tch, so I KNOW she'd complain if it was an issue!).
Dave