Abstract
A model, combining acoustical radiosity and the image source method, including phase shifts on
reflection, has been developed. The model is denoted Phased Acoustical Radiosity and Image
Source Method (PARISM), and it has been developed in order to be able to model both specular
and diffuse reflections with complex-valued and angle-dependent boundary conditions. This paper
mainly describes the combination of the two models and the implementation of the angledependent
boundary conditions. It furthermore describes how a pressure impulse response is
obtained from the energy-based acoustical radiosity by regarding the model as being stochastic.
Three methods of implementation are proposed and investigated, and finally, recommendations are
made for their use. Validation of the image source method is done by comparison with finite element
simulations of a rectangular room with a porous absorber ceiling. Results from the full model
are compared with results from other simulation tools and with measurements. The comparisons of
the full model are done for real-valued and angle-independent surface properties. The proposed
model agrees well with both the measured results and the alternative theories, and furthermore
shows a more realistic spatial variation than energy-based methods due to the fact that interference
is considered.
Original language | English |
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Journal | Journal of the Acoustical Society of America |
Volume | 138 |
Issue number | 3 |
Pages (from-to) | 1457–1468 |
ISSN | 0001-4966 |
DOIs | |
Publication status | Published - 2015 |