Goodman, you sound like a victim of a bad neighbor at some point which, if that's the case, you have my sympathy, bad neighbors just suck out loud...
However, I think the OP is looking for something simple in the sense that they may want some background music outside that's at the same level as inside, this could be fairly low or it could be ear-shattering, impossible to tell from the information here. In addition to this, they could live half a mile away from their next door neighbor.
Just more food for thought... -TD