Styrofoam is a trademark brand of polystyrene foam used in the construction of disposable coffee cups, coolers and even household insulation. Styrofoam also offers some soundproofing benefits, but if you wish to soundproof your home, office or recording studio, Styrofoam alone may prove insufficient to meet your needs.
Polystyrene foams such as Styrofoam can help muffle and reduce the presence of any noises from outside the immediate room or environment. It can also help keep interior noises from leaking out, which proves valuable to the recording musician or private business meeting. Sounds are simply vibrations, and polystyrene absorbs these vibrations, or sound waves. Some of the sound can still penetrate the foam, and so it would be inaccurate to call Styrofoam soundproof. At best, its properties are sound resistant.
A Sound Transmission Class rating, or STC rating, refers to the measurement of a sound's ability to pass through a structure, such as a wall. For example, a low STC rating of 25 indicates that sound can easily pass through the wall. A high STC rating of 50 indicates that the wall is virtually soundproof. Styrofoam has no STC rating because it is not specifically marketed as a soundproofing material. However, due to its absorbent quality, Styrofoam insulation can raise the STC rating of a wall when used as a form of insulation. With the right combination of building materials, including a noise-reducing drywall, it can even help soundproof a room.
Styrofoam insulation is the most effective Styrofoam product for reducing sound in a room or environment. The insulation covers the walls from the inside and offers optimum protection. Simply hanging Styrofoam panels in a room may offer a slight improvement in sound reduction, but will prove basically impractical and inefficient for serious soundproofing. Styrofoam also comes in a foam spray that you can use to fill gaps, doorjambs and frames through which sound travels. The foam spray can also help you muffle sounds on a small scale.
Aside from its limitations, Styrofoam and other polystyrene foams raise some environmental concerns due to the release of hydrocarbons into the atmosphere, as well as their exhaustive manufacturing process and their impact on landfills. If you just want to soundproof a room quickly, you can purchase acoustic panels specifically designed for soundproofing. Most are simple to install, as they hang directly onto the wall surface.