Prediction of sound-pressure level in an occupied enclosure

In a room with inadequate sound absorption, occupants may suffer from low speech intelligibility due to the high noise level resulting from human activities. For effective communication, they tend to raise their voices. In the present study, a method which takes into account the effect of raising voices is derived to predict the variation of A-weighted sound level inside an enclosure in which the number of occupants changes with time. Site measurements are also performed in a canteen of capacity around 250. The model predicts the variations of A-weighted sound levels with a number of occupants with sufficient accuracy for engineering applications.