An accurate and practical surface impedance boundary condition in the time domain has been developed for application to broadband-frequency simulation in aeroacoustic problems. To show the capability of this method, two kinds of numerical simulations are performed and compared with the analytical/experimental results: one is acoustic wave reflection by a monopole source over an impedance surfac...

A deductive approach is used to predict vowel and consonant places of articulation. Based on two main criteria, viz. simple and efficient use of an acoustic tube, along with maximum acoustic dispersion, the Distinctive Regions Model (DRM) of speech production derives regions that closely correspond to established vowel and consonant places of articulation.

We have calculated the phonon frequencies of KC1 along symmetry directions using an approach which is a combination of the frozen phonon and force constants methods. We also calculated Griineisen parameters for all modes at X and L points in the Brillouin zone. Finally, the slope of acoustic dispersion curves around zone center were used to calculate the three independent elastic coefficien...

Acoustic modelling can be informative in the analysis and design of room and concert hall acoustics. There are two types of acoustic models, geometric and wave-based. Geometric models assume sound propagation is ray-like and therefore suited to high frequency room impulse response (RIR) estimation. Wave-based methods are founded on a discrete numerical solution to the wave equation and are ther...

We report on stress induced changes in the dispersion relations of acoustic phonons propagating in 27 nm thick single crystalline Si membranes. The static tensile stress (up to 0.3GPa) acting on the Si membranes was achieved using an additional strain compensating silicon nitride frame. Dispersion relations of thermally activated hypersonic phonons were measured by means of Brillouin light scat...