Sound isolation in construction systems separating occupied spaces in all types of buildings is a necessity. This guideline calls "for improved acoustical analysis of assemblies, components and installation methods, and a more detailed inspection process beyond the minimum requirements traditionally found in building codes." Features: -- The current level and approach of sound isolation requirements in the building code need to be upgraded. They are currently insufficient to meet occupant needs. This guide provides two grades of acoustical performance: acceptable and preferred performance levels for air-borne and structure-borne noise. Both recommendations exceed the current code minimum. -- As sound-rated assemblies are installed in buildings, flanking paths and sound leaks can degrade their acoustical performance. Specific design and evaluation techniques for managing this potential degradation are provided in this guideline.