Doug writes from Dublin, Ohio: "I want to reduce the amount of noise between my office and family room. I am working with an existing interior wall that is open. The wall is constructed using 2 x 4's with 5/8 sheetrock. Does R-13 or R-15 have an advantage over R-11 in reducing noise? If yes, how much?"

Answer: R-value is a measure of thermal performance, not noise control. The rating for sound is STC or Sound Transmission Class, a quantifier used to rate walls, doors and windows for their effectiveness in blocking sound. STC ratings are based on testing the whole wall and the higher the STC rating, the more acoustic value the wall has. Interior wall assemblies are generally tested with 3-1/2" insulation. Since the 2X4 wall you want to insulate is an interior wall between two rooms, we recommend using a 3-1/2" insulation product, either standard R-13 or higher density R-15, although I don't have any data that says increasing insulation density improves STC rating.

Clicking on the highlighted words in this sentence will take you to the Owens Corning Web page presenting QuietZone® noise control solutions for the home. The products in this section are specifically designed for noise control. You will need to check with local building materials retailers for availability.