A field survey on sound power level and spectrum of Japanese road vehicles

Abstract

For precise prediction and appropriate countermeasure of road traffic noise, to grasp the sound power level and power spectrum of running vehicles is important. In Japan, there exists a road traffic noise prediction model “ASJ RTN-Model 2013,” which provides a simple sound source modeling and simple calculation methods of the noise propagation. Recently, vehicles with good fuel-efficiency such as hybrid vehicles are increasing in the category of passenger car. Such vehicles may have less noise emission than previous gasoline engine vehicles. The authors conducted field surveys to grasp the noise of the current road vehicles especially in the category of passenger cars. As a result of that, in terms of A-weighted sound power levels, which can be expressed as a function of running speed, the difference between gasoline engine vehicles is quantitatively discussed. As for the power spectrum, there is no appreciable difference between gasoline engine vehicles and hybrid vehicles. However, both types of vehicle...