A model for calculating the noise absorption capacity of nonwoven fiber webs

Nonwovens can be used as noise control elements for a wide range of applications. This paper suggests a numerical method for calculating their acoustic performance using the theory of Zwikker and Kosten on sound propagation through porous media. The results for nonwovens made from acrylic fibers, cotton, and polyester are in fair agreement with experimental findings. The model yields the noise absorption coefficients of fiber webs as a function of their thickness and porosity. This relationship might serve as a guideline for the optimal design of passive control components made of nonwovens.