2017 Volume 38 Issue 6 Pages 287-294
In order to predict the equivalent continuous A-weighted sound pressure level (LAeq) of road traffic noise in areas facing roads, knowledge of the insertion loss of buildings against road traffic noise is needed. The authors previously proposed formula F2012 for predicting the insertion loss of detached houses against road traffic noise using a point sound source model. F2012 is applicable to the evaluation of the Environmental Quality Standards for Noise in Japan (EQS). F2012 is composed of four factors: direct sound Edir, reflections Eref, first diffractions Edif,1, and others Edif,2. However, it is not easy to find the values of the parameters for Eref and Edif,1 in spite of their smaller sound energies than Edir and Edif,2. A simple calculation is essential for the evaluation of EQS. Therefore, a simplification of F2012 is examined and the simplified formula F2012* is proposed in this paper. In addition, a means of simplifying the computation of F2012* is examined.