Just enclosed covered deck that was constructed on post and pier. Floor is 2x8s w/ 3/4" plywood on top. No insulation or anything under. Flooring not down yet, and neighbor is complaining that kids running on bare floor sounds like hammers pounding. Got half way through installing laminate floor with regular foam like underlayment, and neighbor again complained when kids were playing on the new floor. I saw a noise reducing underlayment at Home Depot, which may help a little, but I doubt will completely solve the problem. Don't need to completely eliminate noise because he is a neighbor, and not living on floor below or anything, but I want my kids to be able to play without bothering them. Would appreciate any suggestions on how to sound proof floor at this point.