Abstract
The noise problem for passenger cars is of increasing concern for the motorcar industry. Continuous noise has been shown to cause tiredness and a decrease of driver's reflexes. The four grades used by the industry for noise nuisance are discussed. The main causes of noise and vibration, viz. : the engine and its various parts, the exhaust system, the transmission system, the tyre-road contact, wind noise and various by-sounds, are discussed, as well as the vibration frequencies and the way these frequencies are transmitted through the vehicle. The noise recording equipment's is described as well as some means of isolation.