Roxul Safe'N Sound is a fire and sound deadening insulation for interior partition walls or floors. This is a stone wool-based insulation that is made from natural stone and recycled content. Its a green product that provides superior sound absorbancy and fire protection for overal comfort and safety. It is not intended for a thermal application like insulating exterior walls.
Both open and closed cell foams have air barrier qualities that can help reduce noise from outside the building envelope (i.e. airplanes and automobile traffic). The half pound open cell foam's density offers additional sound absorbing qulaitites. Neither foam, however, is exceptionally effective in reducing vibrational impact noises.
Sound deadening is used to reduce noice transfer through walls and floors such a heavy walkers or a loud noise from the next room. Typically sound proofing or deadening needs to be thought of as a syste, (i.e sound batt/foam insulation combined with acoustical caulking, staggered studding, resilient channel, sound eadening drywall, etc. The more elements that are introduced to the wall or ceiling assembly the better the sound protection.