The development and evaluation of a method for understanding the impact of transmission loss on the overall noise attenuation of finite barriers

The purpose of this study is to evaluate the impact of transmission loss on the overall noise reduction obtained from finite barriers. The noise attenuation ability of barriers is understood to be a consequence of sound waves diffracting around their edges. Although the presence of transmission loss is acknowledged, its significance in affecting noise attenuation is usually not considered a priority in barrier design. This study incorporates the Fresnel Number concept for predicting theoretical insertion loss of a finite barrier and compares these predictions to experimental observations. The experiments performed in this study offer a method to isolate the transmission loss component from diffraction based noise attenuation. This isolation allows the comparison of these two factors in the overall barrier performance. The influence of transmission loss is found to be significant and the findings encourage its consideration in designing solutions to modern noise control challenges.