The external and middle ears can be seen as a whole system able to convert the acoustical energy from the free field to a semi-confined media dedicated to an efficient transduction of the signals of interest. Among species this configuration is highly dependent on the environment and the usage. The work will focus on the simulation by the finite element method using the COMSOL software of the acoustical coupling of a vibrating membrane placed at the interface between an acoustic wave guide and a semi-confined network of cavities. Methods developed to study the design of microphones are well suited. In particular the methods that help study the impact of a non planar shape of the back of the cavity just behind the vibrating membrane. It will be asked to demonstrate how these configuration help creating optimized set-up condition. In a second phase, design rules inspired by anatomical specificities will be extracted. The optimisation of three parameters is of main interest : directionality, sensitivity to a larger range of input signals and spectral responses within a narrow or large frequency band. In the meanwhile a lumped model based on the acoustic-mechanic-electrical analogy of the complete system will be done on the basis of a preliminary study demonstrating the interest in using a system-level simulation tool (ASYGN) to reproduce the performance of the organ on one side and the artificial transducers inspired from the organ on the other side.