A Simple Method to Estimate the In Situ Performance of Noise Barriers

Noise barriers are usually classified attending to their intrinsic acoustic characteristics. This is standardized by the European Standards EN 1793, parts 2 and 6, in which a single parameter, DLR or DLSI, is defined in order to quantify the sound insulation performance of noise barriers. However, the final performance of a noise barrier, quantified by the so-called insertion loss, IL is not only dependent on the insulation provided by the noise barrier, but it is as well affected by geometrical aspects and the acoustic characteristics of the environment where these noise-reducing devices are placed. In this work, we explore the relationship between the insertion loss and the acoustic insulation by means of numerical methods. Moreover, the authors propose a simple way to predict the insertion loss from a purely acoustic numerical simulation in which this parameter is obtained for a completely rigid noise barrier, and knowing the noise barrier’s sound reduction index, in one third octave bands.