Acoustic representation of absorbing material in the time domain using finite impulse response filters in discrete Huygens modeling

Abstract

In recent years there has been renewed interest in numerical methods in the time domain in view of applications such as sound synthesis and the need to obtain the impulsive response of acoustic systems. Discrete Huygens Modeling (DHM) is one of the available methods that offers certain interesting features, such as relatively simple computational implementation and low computational cost. Although the method has been widely used in the field of electromagnetism, its application in acoustics is still in a limited condition, especially in relation to the adequate description of absorption materials at the boundaries of the analyzed domain. The main objective of this article is to show the applicability of FIR - Finite Impulse Response filters in the representation of absorbing materials in the DHM method, without significantly degrading their computational performance. In this work, DHM was used to indirectly obtain the frequency response functions of an acoustic cavity, with and without the presence of absorption materials. Numerical results and computational times were compared with models developed in Finite Elements (FE). Excellent agreement was observed between the methods, with great advantage for the DHM method in terms of computational cost.