In supporting the development of all-wood floor systems without lightweight gypcrete or concrete topping, APA conducted a series of acoustic tests for code compliance based on sound transmission class (STC) and impact insulation class (IIC) ratings. Detailed descriptions for STC and IIC ratings are provided in APA Design/Construction Guide: Noise-Rated Systems, Form W460. The results are presented in this publication. The double-layer floor assembly (19/32 Performance Category top layer over 23/32 Performance Category base layer) provides similar acoustic performance to the single-layer (1-1/8 Performance Category) floor assembly.