Comparison of finite element formulations for sound transmission modeling of the outer ear

The work described in this paper is part of a broader research activity on the development of a virtual ear. The present study focuses on the tympanic membrane and auditory canal modeling, which are main components in sound transmission. The standard finite element method (FEM) and alternative methods (the spectral method and the generalized finite element method) suitable for modeling sound propagation at high frequencies were applied. Two domains (fluid and structural) for the auditory canal and the tympanic membrane, respectively, were considered in order to evaluate the coupling of different methods and to apply a fluid-structure interaction formulation. The analysis results on an anatomical finite element model, which include pressure distribution in the auditory canal and displacement distribution and frequency response of the tympanic membrane, confirm experimental and theoretical data reported in the literature. The spectral and generalized FE methods were implemented and applied to approximated three-dimensional models of the outer ear. The validation of such methods with standard FEM simulation at increasing mesh density shows their computational advantages in terms of reduced mesh density required for accurate results.