A SIMPLE METHOD FOR THE CALCULATION OF NOISE ATTENUATING BY A FINITE-LENGTH BARRIER

A practical expression for the estimation of sound attenuation by a ba rrier of finite length is presented. The sound attenuation is determin ed by taking account of sound contributions from rectangular sections of a plane barrier located between a point source and a receiver. The expression for the attentuation due to a finite length barrier is fina lly formulated by combining the attentuations due to semi-infinite pla ne barriers. Scale model experiments were carried out to check the val idity of the expression and the results showed good agreement between them. The calculated values were also compared with the values estimat ed from the methods of ISO/DIS 9613-Part 2 and the Fresnel-Kirchhoff t heory. It is shown that our expression is useful and applicable to the design of a finite length barrier when the sound source has a broad b and spectrum and the overall sound pressure level is a matter of inter est.