Styrophone is often made from what type of closed-cell polystyrene?
Styrophone: A styrophone is an acoustic device made from expanded polystyrene foam (often referred to by the genericized trademark "Styrofoam") and it goes toot toot. Styrofoam: Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam currently made for thermal insulation and craft applications.
Styrofoam