Effect of finish floor on airborne sound insulation of concrete slabs

It is usually assumed that the finish floor does not significantly affect the airborne sound insulation of a floor–ceiling assembly, as the finish floor contributes only a fraction of the overall mass. However, it is conceivable that the finish flooring changes the coupling of the assembly to the receiving room, and anecdotally, occasional large changes in transmission loss at some frequency bands is observed with changes in finish floor. The authors systematically evaluate differences in transmission loss of concrete slabs with different finish floors and attachment methods and compare the differences measured in two acoustical testing laboratories.