Murray Hodgson
Occupational Hygiene Prog./Dept. of Mech. Eng., Univ. of British Columbia, 2324 Main Mall, Vancouver, BC V6T 1Z4, Canada
This paper reviews the state of the art of noise (steady-state sound-pressure level and reverberation time) prediction in industrial workrooms. First, some experimental results are presented to illustrate typical workroom noise characteristics. The room-acoustical parameters that must be included in a comprehensive prediction model are discussed. Available theoretical prediction approaches (diffuse-field theory, method of images, ray tracing, simplified models), with their associated advantages and disadvantages, are reviewed. Ray tracing, the most comprehensive approach, is described in some detail. The results of on-going work aimed at determining applicable values of the input prediction parameters (surface and furnishing absorption coefficients and furnishing densities) are discussed. The main problems associated with workroom noise prediction are summarized. Finally, two case studies, one involving comparing measured and predicted noise levels in a power generating station and another involving predicting the effectiveness of noise-control treatments in a workshop, are presented.