An absorptive acoustic material used to control sound reflections. True acoustic foam is a specially engineered type of foam — very different from bedding foam, packing foam, and other types, which are made from polyesters, polyethers, polyurethanes, and other materials. Acoustic foam has other characteristics such as “open-cell” design, which means that the foam contains many tiny air pockets. Acoustic foam should also be fire-rated for safety.
As a sound wave passes through acoustic foam, its energy is converted to heat, reducing its amplitude.