An assessment of the accuracy of a hybrid room acoustics model with surface diffusion facility

Computer modelling of acoustics in enclosures has developed into various fo rms, none of which have pet demonstrated 100% accuracy. This paper, therefo re, details a study of room acoustic computer modelling that highlights wea knesses with existing modelling techniques. The study illustrates that for accurate prediction of many room acoustic parameters the modelling of surfa ce reflections needs to be refined. Accounting for scattering in the modell ing of all reflection orders would improve accuracy in the time domain and assist in the prediction of parameters such as reverberation time, early de cay time and clarity index. Allowing the directivity of scattered energy to be modelled would improve spatial accuracy and prediction of lateral energ y fraction. Definition of scattering parameters in the frequency domain wou ld also improve predictive accuracy, especially at low frequencies, where g eometrical modelling is particularly inappropriate. Improvements in accurac y may also be achieved by including the modelling Of barrier edge-diffracti on, especially for seating areas behind balcony fronts. (C) 2000 Elsevier S cience Ltd. All rights reserved.