noise reduction gym dividers acoustical rating automatic walls 10650 folding doors NOISE REDUCTION The combination of these elements creates an exceptional sound barrier that must be heard to be believed. Skyfold has been approved by many top architectural firms in the world for use in spaces where Noise reduction is critical. ís Noise reduction capabilities do not deteriorate over the life of the wall. Autolift Wall systems have been tested with ASTM E90 for Noise reduction and the tests yielded an STC rating of 51. Better yet, the system was shown to retain its sound-separation capabilities over the life of the wall! There are also a variety of panel finishes available that offer desired NRC properties.