Acoustic Absorption with Material in Pieces and Back Air Layer

The sound absorption coefficient of three different materials is proved in a reverberation room against different layouts of the material and different back air layers, compared to those results where the same material is placed as a single piece. With the analysis of the data, a linear regression model is established in order to predict, for certain frequencies, the alteration produced in the absorption coefficient by using the same amount of material but placing it in patches separated from each other, instead of in one piece, and at different distances from the wall. The model is validated and proven to be robust and it is shown to be applicable to a variety of materials. It becomes a simple predictive tool which allows to estimate in situ the improvement in the absorption property of an absorbent material due to the separation of the patches.