An acoustical insulation foam having, either with or without elastification, an Asker C hardness of less than about 65, a density of about 5 to about 150 kg/m3, a cell size of about 0.05 to about 15 mm, an open cell content of 0 to about 100 volume percent, a thickness of about 1 to about 200 mm, and a width of about 100 to about 3000 mm; comprising; (A) one or more alkenyl aromatic polymers, (B) one or more substantially random interpolymers and (C) optionally, one or more nucleating agents and (D) optionally, one or more other additives; and (E) one or more blowing agents.