Article
Numerical Validation of Head-Related Transfer Functions computed using Immersed Boundaries (en)
* Presenting author
Abstract:
Head-related transfer-functions (HRTFs) describe the free-field sound transmission to the ears and thus contain all cues that are needed to simulate spatial hearing. HRTFs are thus one of the fundamental ingredients in most virtual and augmented reality systems. They can be obtained experimentically or by numerical simulations. One possible way of obtaining HRTFs is to numerically solve the Euler or wave equation in the time or frequency domain based on a 3D mesh of a head.In this contribution finite difference time domain (FDTD) simulation techniques are investigated. Therein, the Euler equations are solved using an immersed boundary (IB) method. The IB method manipulates the governing equations by adding a volume fraction and a linear friction term. Realistic acoustic boundary impedances can be received by adjusting the volume fracion and/or the linear friction term.The method will be validated by the analytic solution of the diffraction around a rigid sphere and the simulation of a human ear as well as a human head. Here, the FDTD method is compared with boundary element method (BEM) simulations. FDTD and BEM are the most studied HRTF simulation methods. Advantages of FDTD are that no specially prepared grids are necessary and its parallelization possibilities.