Diffusing boundaries in the digital waveguide mesh and their effect on reverberation time

TY - GEN

T1 - Diffusing boundaries in the digital waveguide mesh and their effect on reverberation time

AU - Murphy, Damian

AU - Southern, Alex

AU - Shelley, Simon

PY - 2008

Y1 - 2008

N2 - The digital waveguide mesh is often used to simulate the propagation of sound waves in an acoustic system. The diffusing layer is an approach that has been shown as appropriate for simulating diffuse boundary reflections as this is a fundamental acoustic property of real surfaces. Incoming wavefronts are rotated randomly according to a chosen probability function at a layer of mesh nodes adjacent to the boundary of interest. Although this method offers a high level of control and consistency, the nature of the interaction between terminating boundary function and incident wave is altered with an associated potential impact on the resultant wave propagation behaviour for the rest of the space. This paper explores this effect based on impulse response measurements obtained from a simulated space. Results are presented demonstrating the effect diffusion modelling has on early reflections and that depending on the conditions imposed increased boundary diffusivity can lead to either an increase or decrease in reverberation time. Standard objective measures are used to demonstrate the perceptual effect of increased boundary diffusivity on the spatially encoded diffuse field for the modelled space.

AB - The digital waveguide mesh is often used to simulate the propagation of sound waves in an acoustic system. The diffusing layer is an approach that has been shown as appropriate for simulating diffuse boundary reflections as this is a fundamental acoustic property of real surfaces. Incoming wavefronts are rotated randomly according to a chosen probability function at a layer of mesh nodes adjacent to the boundary of interest. Although this method offers a high level of control and consistency, the nature of the interaction between terminating boundary function and incident wave is altered with an associated potential impact on the resultant wave propagation behaviour for the rest of the space. This paper explores this effect based on impulse response measurements obtained from a simulated space. Results are presented demonstrating the effect diffusion modelling has on early reflections and that depending on the conditions imposed increased boundary diffusivity can lead to either an increase or decrease in reverberation time. Standard objective measures are used to demonstrate the perceptual effect of increased boundary diffusivity on the spatially encoded diffuse field for the modelled space.

KW - Acoustics

KW - Diffusion processes

KW - Digital waveguide mesh

KW - Finite difference time domain

KW - Reverberation

UR - http://www.scopus.com/inward/record.url?scp=50649087729&partnerID=8YFLogxK

U2 - 10.1109/ISCCSP.2008.4537464

DO - 10.1109/ISCCSP.2008.4537464

M3 - Conference contribution

AN - SCOPUS:50649087729

SN - 9781424416882

T3 - 2008 3rd International Symposium on Communications, Control, and Signal Processing, ISCCSP 2008

SP - 1498

EP - 1503

BT - 2008 3rd International Symposium on Communications, Control, and Signal Processing, ISCCSP2008

T2 - 2008 3rd International Symposium on Communications, Control, and Signal Processing, ISCCSP2008

Y2 - 12 March 2008 through 14 March 2008

ER -