Absorbtion

Absorption refers to the absorption of sound waves by a material. The absorption is the "missing piece", when comparing the total reflected and transmitted energy with the incident energy.

It is the property of a material that changes acoustic energy into usually heat energy. A material or surface that absorbs sound waves does not reflect them. Absorption of a given material is frequency-dependent and is affected by the size, shape, location, and mounting method used.

A good sound absorber is normally a porous material. Mineral wool, glass wool, and micro perforated plates work as sound absorbers.

Absorption is not a single mechanism of sound attenuation. Propagation through a heterogeneous system is affected by scattering as well.

Acoustical absorption is represented with the symbol A.

*This article is licensed under the |GNU Free Documentation License. It uses material from the Wikipedia article http://en.wikipedia.org/wiki/Absorption_(acoustics)