[header] How to use viscoelastic damping glue and drywall to soundproof a room [title] Construct the framing as normal. [step] Your results will be improved if the framing is decoupled. Also consider a bit of insulation in the wall if there's none there now. 
[title] Install a sheet of drywall to the frame. [title] Before installing the next sheet apply acoustical sealant around panel perimeter and around any electrical boxes.