Optimization of vented earpiece designs using the finite element method
* Presenting author
Vented earpieces equipped with multiple receivers and microphones operated using suitable algorithms offer the possibility to achieve acoustically transparent sound presentation by conserving the acoustic properties of the open ear, see also Schepker et al. (this conference). Acoustic transparency should ideally hold for all external sound sources, which translates into the requirement that the relative transmission paths between microphones located in the earpiece and the eardrum should be independent of the positions of external sound sources. Since measurements made on various prototypes showed different degrees of dependence on external source positions, numerical simulations using the Finite Element Method (FEM) were performed to better understand the impact of the microphone positions, with the ultimate goal to optimize the earpiece design for acoustic transparency. Both commercial and custom implementations of the FEM were used, considering generic as well as individual 3D geometries of the outer ear. For the existing prototypes, the dependence on external source positions observed in the measurements could be reproduced by the numerical simulations, indicating the suitability of the method. A strategy to optimize the earpiece design is proposed.Funded by the Deutsche Forschungsgemeinschaft (DFG) – Projektnummer 352015383 – SFB 1330 A4 and C1.