Analysis of airborne sound insulation and impact sound pressure level provided by a single partition containing a heterogeneity

This paper studies the acoustic behaviour provided by a single infinite elastic partition dividing an infinite acoustic medium, containing two-dimensional (2D) heterogeneities placed parallel to the layerʹs surfaces, which simulate the presence of fittings such as pipes. The problem is solved in the frequency domain using the boundary element method (BEM). Only the surfaces of the heterogeneities are discretized, since 2.5D Greenʹs functions for the single layered media, bounded by acoustic media, are used. Time domain responses are also computed by applying a (fast) Fourier transform to the responses obtained in the frequency domain. The heterogeneities are assumed to be either rigid, free, fluid-filled or elastic-filled inclusions. The simulated models are used to study the contribution of the heterogeneities to the final airborne sound insulation and impact sound pressure level provided by a single partition. It was found that both airborne sound insulation and impact sound pressure level may be influenced by the presence of the heterogeneity at higher frequencies.