Prediction of insertion loss of detached houses against road traffic noise using a point sound source model: Simplification of prediction formula F2012

Abstract

In order to predict the equivalent continuous A-weighted sound pressure level (L_Aeq) 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 E_dir, reflections E_ref, first diffractions E_dif,1, and others E_dif,2. However, it is not easy to find the values of the parameters for E_ref and E_dif,1 in spite of their smaller sound energies than E_dir and E_dif,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.