Sound quality approach on vehicle interior and exterior noise. Quantification of frequency related attributes and impulsiveness.

Abstract

In case of vehicle noise, there exist two subjective feelings that have not been well quantified yet by utilizing existing psychoacoustical parameters.Those are booming sensation due to the presence of prominent low frequency interior noise and impulsiveness of the exterior noise at idel due to the knocking phenomenon from a diesel powerplant.For booming sensation, it is successfully quantified in our laboratory by utilizing the subjective response to booming sensation as the weighting function to the sensation level in case of stationary noise, i.e, interior noise at cruising mode.In order to extend this measure for applying this concept to non-stationary noise, i.e, acceleration noise, a new psychoacoustical measure named booming index was developed here.For the development of a measure representing impulsiveness of diesel exterior noise, exterior noise at idle is evaluated and the relation between the subjective result and the newly proposed measure named IMPULSE is discussed.This newly proposed measure is calculated with the average sound pressure that exceeds the root mean square value of the time waveform of the sound pressure.