Prediction of sound around a corner in long corridors

Abstract

An L‐shape section is a prime consideration in the design of corridors in modern buildings. Similar to a straight corridor, the direct sound field dominates the sight‐line region in the near field. However, there is no contribution from the direct sound field when the receiver locates around the corner at the shadow zone. The reflected sound field becomes more important as the receiver moves further from the bend. The present study examines the propagation of sound along a long space with an L‐shape section. A numerical model using an image‐source method is developed for the prediction of sound transmission along the L‐shape section of a long corridor. The reverberation times are predicted by the proposed numerical model. In particular, the respective sound fields at two octave bands (500 Hz and 2,000 Hz) are obtained. The noise levels at these two octave bands are needed for the computation of the rapid speech transmission index. This information is often used to conveniently assess the speech intelligibility of a communications channel. The proposed image source model is validated by comparing with field measurements conducted in an L‐shape corridor and also conducted in a scaled model in an anechoic chamber.