Expert Insight

• According to Sweetwater Music Instruments & Pro Audio, two problems associated with recording studios and performance spaces are slap and echo. Echo occurs when sound bounces off the walls, reverberating through the space. Slap has a sound that mimics the noise created by slapping your hands together, as the noise seems to linger in the air. Acoustical foam diffuses the sound and makes it less noticeable to your ears.
  
  

Acoustic Foam Benefits

• Acoustical foam is a cost-efficient alternative to other methods of soundproofing. As of 2011, pieces of acoustic foam sold for around $100 each. The foam comes in different sizes for fitting different types of walls and cuts easily with a utility knife or scissors for a custom fit. Apply the foam with spray adhesive or nails. Sweetwater recommends covering at least 25 percent of the room for proper soundproofing and up to 75 percent for recording studios and more frequently used rooms.
  
  

Foam Types

• Acoustic foam consists of foam pressed or molded into different shapes. The wedge design features different wedge shapes arranged along the foam in a zigzag pattern. The pyramid foam has lines of pyramids moving across the foam and from the top down to the bottom. Foam Order recommends arranging the pieces on the walls in different ways, such as wedge pieces facing left to right next to wedge pieces facing up and down. The arrangement absorbs and diffuses sound waves in different ways.
  
  

Diffusing Sound

• Acoustic foam works by blocking and disusing sound waves from inside and outside the room. Rooms without any type of soundproofing let sound waves move directly through the walls because nothing stops the noise. When the same sound waves reach the foam, the shape of the foam pushes the sound into different areas of the foam. As the sound bounces around the foam, it diffuses, and less sound escapes from the room. The more foam you have on the walls, the less sound escapes.