Jeff writes from Syracuse, Indiana: "I'm insulating the ceiling in a basement with fiberglass to control sound transfer to the room above. Give me a ballpark estimate of reduction can I expect to see assuming resilient channels and drywall? What would be the difference in using 4, 6, 8 inch thick batts will the sound control capabilities increase? Is there a point where more will do no more good?"

Answer: The thicker the insulation and drywall with the use of resilient channel, the higher the STC rating (Sound Transmission Class - a quantifier used to rate walls, doors and windows for their effectiveness in blocking sound). The higher the STC rating, the more acoustic value the wall has. If you will provide information about your current wall assembly and the wall assembly you plan to go to, I can have one of my friends at Owens Corning estimate the difference in STC ratings.