Study on Evaluation Methods of Sound Emission Characteristics Measurement of Moving Vehicles - Method of Time Constant Effect Correction for Measurement of Moving Vehicles Sound

An essential requirement for an effective control of noise is to understand the sound emission characteristics of moving vehicles. However, when there is relative motion between the microphone and the sound source, it is difficult to determine the actual noise characteristics due to the effect of the sound level meter's time constant. This paper describes the results of a study that identifies the relation between the moving and stationary conditions of the sound source, and develops a method to correct for this variation.