FloorMuffler Flooring Underlayment Acoustical and Moisture Barrier for Wood and Laminate with Self Sealing Overlap System 100sf The highest rated and most effective acoustic barrier on the market. Most Effective underlayment for reducing foot fall noise. IIC74/STC73 Ideal choice for most laminate, engineered and solid hardwood flooring applications. Light, strong and flexible, making it easy to handle and install in nearly all conditions. Mold and mildew resistant.