Development of Elasto-Acoustic Integral Equation Based Solver to Assess/Simulate Sound Conducting Mechanisms in Human Head
Abstract
The project objectives were (a) to construct an accurate and efficient numerical simulation tool capable of handling a variety of aspects of wave propagation and the resulting energy flow in a human head subject to an incident acoustic wave propagating in the surrounding air; and (b) to develop understanding of mechanisms of energy transfer to the inner ear/cochlea region and quantitatively estimate the amounts of energy due to various sound-wave conduction paths. The problem is rather unique in that it involves very small amounts of energy transferred from air to a dense inhomogeneous object: such small energy flows are relevant only because of the exceedingly high sensitivity of the animal hearing apparatus. Therefore, in order to be able to achieve an adequate accuracy in the solutions for the pressure and its derivative, we have chosen to base our analysis on surface integral formulations for multi-region topologies with individual piecewise homogeneous sub-regions. A generalization of this approach to problems involving collection of piecewise homogeneous and inhomogeneous material regions was formulated. We constructed a detailed model of human head geometry which contains essential features needed to study energy transfer to the cochlea region. Since details of the geometry appear to be critical in controlling the energy flow to the cochlea region, a significant fraction of the effort was devoted to the construction of an anatomically faithful geometry model. The model was subsequently used in numerical simulation providing insight into the energy flow to the cochlea region through air and bone conduction paths. The main findings of our analysis were: (i) The distributions of pressure and velocity fields depend in very different ways on the object geometry, hence the behavior of the resulting energy flux may be highly nontrivial and difficult to predict without an actual computation. (ii) The resonances associated with the outer ear canals emanate energy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 09, 2013
- Accession Number
- ADA590919
Entities
People
- Elizabeth Bleszynski
- Marek Bleszynski
- Thomas Jaroszewicz