With the current state of the art, it is very challenging to solve a full FEmodel of an undamped vibro-acoustic system into the mid-frequency domain, let alone a locally damped one. The Wave Based Method (WBM) is well suited for this full- system modelling, since it has a very good convergence rate as compared to the FEM and BEM. The application of the WBM is, however, limited to convex domains. To overcome this limitation, hybrid Finite Element - Wave Based approaches have been developed. This contribution extends the family of hybrid FE-WB methods towards coupling WB models for acoustics with FE models for poro-elastics. The method benefits from the computational efficiency of the WBM for the acoustic calculations, without losing the FEM’s ability to model the layered and complex poroelastic material in detail. As previous work focused on the (u,U)-formulation of the poro-elastic problem, containing 6 DOFs per node, the current approach further reduces the computational cost by using a (u,p)-formulation with only 4 DOFs per node. The presented method is validated with a numerical example. This study considers the interior acoustics of a rigid-walled cavity where one of the walls is covered with trim layer. ; status: accepted