|Project||Room acoustics modelling using 2-D digital waveguide mesh structures|
|Geometrical acoustic methods such as ray-tracing and image-source
techniques are often used to model the acoustic properties of a room but
are limited to being valid only for high frequencies. At low frequencies
diffraction and the effects of room modes cannot be neglected. This
project examines the problem of modelling the two dimensional propagation
of sound within an enclosed space by using a digital waveguide mesh model,
with the results being valid across the whole frequency spectrum.
Digital waveguide mesh models have provided an accurate and efficient method of modelling the properties of many resonant structures, including acoustic spaces. 2-D rectilinear and triangular mesh topologies have been used extensively to model plates and membranes and are presented here within this context as potential analogues to 2-D acoustic spaces. Impulse response measurements are taken and comparisons made regarding the spectral content and the associated properties when compared with standard room acoustic parameters. Enhanced mesh structures have been examined using frequency warping techniques and high resolution sampling rates. The 2-D triangular mesh is shown to be considerably superior to the rectilinear mesh in terms of the measurements taken, with a further significant improvement being made by using the same mesh oversampled to a much higher resolution to improve the bandwidth of the measured impulse responses.
The impulse response measurements obtained from these models can be used in an appropriate Auralization scheme to recreate exactly the acoustic properties of the virtual space for any given sound source placed within it.
|Staff||Dr Damian Murphy, Prof David M Howard, Gui Campos|
|Funding||University of York Studentship, EPSRC application|