When we moved into our house a while ago I knew I needed sound resistant (absorbing) curtains for my bay window and my sliding glass door. If you don't want to buy used (the link above) you can try going to a Calico Curtains if you have one in your area. That's what we did. I specified what I wanted and they made very nice three layer heavy curtains. The first layer (the one you and your wife would see) would be made up of heavy but not super-tightly threaded material. CC has many nice colors and patterns to suit matching in your home. The next layer is heavier, denser material, and the last (back) layer is very dense but soft - backed by a very tightly woven layer. Hmm, I guess that's really four layers. The idea I had was to have the sound hit layers that were progressively harder to get through, with the last dense enough to keep the sound waves from hitting the glass and bouncing back. Maybe you don't have to go as far as I did, but these curtains (which when pulled closed are not flat - they're undulating, I guess) seem to get the job done nicely. Problem is getting something like this custom made was not cheap. But in my case we knew we wanted to stay in this house a good long while, so I wanted to try and get something that had high WAF.
