Acoustic foam is a special foam made to absorb sound. It is available in a variety of thicknesses. Acoustic foam generally has some flame retardant properties. Acoustic panels normally range from 1 inch to 4 inches which is cut from a large block of acoustic foam.

Acoustic foam is cut into  a variety of shapes and  sizes and coated according to the purpose of the foam. Open-celled absorb sound better than close-celled Al foam. The introduction of carbon nanotubes  to polyurethane  foams has improved dampening even more.

Shapes

  • Pyramid
  • Wedge or V cut
  • Flat
  • Eggcrate

Purposes

  • To reduce echo and reverb
  • Improve speech intelligibility
  • Absorb or Diffuse sound

Materials

  • Polyurethane
  • Melamine resin

 

Interesting. A patent was filed on Dec 13, 1962 for an acoustic polyurethane foam. US 3196975 A