Review in sound absorbing materials

This article is a bibliographical revision concerning acoustic absorbing materials, also known as poroelastics. These absorbing materials are a passive medium use extensively in the industry to reduce noise. This review presents the fundamental parameters that define each of the parts comprising these materials, as well as current experimental methods used to measure said parameters. Further along, we will analyze the principle models of characterization in order to study the behaviour of poroelastic materials. Given the lack of accuracy of the standing wave method three absorbing materials are characterized using said principle models. A comparison between measurements with the standing wave method and the predicted surface impedance with the models is shown.