Effects of higher order propagation modes in vocal tract like geometries
Résumé
In this paper, a multimodal theory accounting for higher order acoustical propagation modes ispresented as an extension to the classical plane wave theory. This theoretical development is vali-dated against experiments on vocal tract replicas, obtained using a 3D printer and finite elementsimulations. Simplified vocal tract geometries of increasing complexity are used to investigate theinfluence of some geometrical parameters on the acoustical properties of the vocal tract. It is shownthat the higher order modes can produce additional resonances and anti-resonances and can alsostrongly affect the radiated sound. These effects appear to be dependent on the eccentricity and thecross-sectional shape of the geometries. Finally, the comparison between the simulations and theexperiments points out the importance of taking visco-thermal losses into account to increasethe accuracy of the resonance bandwidths prediction.