VEHICLE NOISE AND VIBRATION CONTROL

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Review of Vehicle Noise Levels

Vehicle manufacturers work with noise and vibration control to fulfil legislation demands and to meet customer requirements.

The exterior noise control work is mainly motivated by legislation demands while interior noise and vibration control work is motivated by driver and passenger noise and vibration comfort requirements.

The motivation for reducing traffic noise is that it is the most important environmental noise source in Europe and in the rest of the world.

About 25 % of the population in Europe is exposed to transportation noise with an equivalent sound level over 65 dB(A). At this sound level
sleep is seriously disturbed and most people become annoyed [2].


Character Of Vehicle Noise
Exterior road traffic noise results from the combined contributions from a large number of different vehicles.

Trucks are typically noisiest followed by buses and motorcycles while cars are the quietest.

The contribution of cars to the overall traffic noise level is however great because of their large numbers (about 80% of the road traffic). For lower speeds, below 40-50 km/h, engine noise including exhaust and intake noise dominates for cars.

For higher speeds, above 70 km/h, tyre-road noise dominates the car exterior noise generation.

For heavier vehicles the engine noise is dominant under most conditions.