Measured and predicted acoustic performance of vertically louvred noise barriers

The paper describes model testing of the acoustic performance of vertically louvred and the corresponding predicted performance using a modified Bound ary Element Method (BEM) program. The program was developed in a previous p hase of the Transport Research Laboratory's research into the performance o f modified barriers. Measurements on 1/20th scale model barriers were carri ed out in a semi-anechoic chamber designed primarily for scale model experi ments to investigate outdoor sound propagation under controlled conditions. It was concluded from measurements in the scale model facility that the mo dified BEM code provided an adequate description of the leakage of sound th rough louvred barriers. The program was subsequently used to examine the pe rformance of various designs of barrier in order to identify likely cost ef fective designs. (C) 2001 TRL. Published by Elsevier Science Ltd. All right s reserved.