Predicting method of insertion loss of road traffic noise by detached houses at areas facing flat road

摘要

In Environmental Quality Standards for Noise in Japan revised in 1998, the problem ofenvironmental noise at areas facing roads is evaluated by obtaining the numbers and the ratesof buildings at which noise levels exceed the standard value. The Standards allow for theestimation of noise levels, instead of requiring actual measurements, in cases where taking theactual measurements would be difficult. In order to estimate noise levels, it is necessary tograsp insertion loss by buildings in an evaluated area. The authors proposed in the previousstudy a simple method to predict insertion loss of road traffic noise by detached houses at areasfacing flat road on base of experimental results. However, the accuracy of this method was notso high because of the restriction of experimental instruments. This time, the method ofexperiment is improved and experiments are performed again. As a result, a more accuratepredicting formula of insertion loss of road traffic noise by detached houses is proposed. Thevalidity of the formula is verified through additional experiments and a comparison with thecurrent methods. This new and simple method is applicable to evaluation of EnvironmentalQuality Standards for Noise.