Vehicle noise and the passenger

Little effort has been put into studying the noise climate inside passenger vehicles. This paper shows that noise levels in motor cars and heavy goods vehicles are unacceptable to the passenger at typical cruising speeds. It is suggested that one factor responsible for this state of affairs is the lack of criteria for acceptable noise levels. Research into the subjective response to noise in motor vehicles, both on the road and in the laboratory, is described. The importance of very low frequencies is shown in determining levels of comfort, as well as the difficulties in accurately reproducing in-vehicle noise in the laboratory. A tentative criterion is given for acceptable noise levels in passenger vehicles and work is described which, it is hoped, will lead to a more precise measure of subjective rating.