Acoustic foam

Acoustic foam is a type of foam used for acoustic treatment. It makes sound waves in the air weaker, thereby reducing their amplitude. It is used to reduce or control noise. Acoustic foams are typically softer and more lightweight than their sound blocking foams. The open and flexible cell structure of acoustic foam acts as a natural soundwave absorber and prevents noises from reverberating off hard surfaces like walls, floors and ceilings. It does this by converting existing sound energy to heat and reducing the ability of soundwaves to bounce back into the room. Depending on how it's used, this type of foam can also enhance the acoustics within a room. Sound absorbing foam cut into pyramid or wedge shapes can be used to manipulate vibrations in a way that improves sound quality.
Acoustic foam can be attached to walls, ceilings, doors, and other places in a room to control noise levels, vibration, and echoes.
Many acoustic foam products are treated with dyes and/or fire retardants.