Yes, they do. Behind the curtains are thick packing blankets. There are also curtains along the left wall. The curtains themselves are also very thick. To balance this on the right wall, there is a blanket hanging, which you can see part of - that has 1/2" foam attached to it's back. The room does not exibit any slap echoes, due to the acoustic treatments, and the peaked ceiling. The beams also break up the sound well.I went to a lot of trouble during the design phase to get the acoustics right.