Reducing noise pollution

Compared to air and water pollution, noise tends to get a low priority.

Still, the European Union estimates that some 20% of its population suffers from noise levels that scientists and health experts consider unacceptable.

That's close to 80 million people being annoyed and getting their sleep disturbed - in Europe alone. And many more live in areas where noise reaches seriously annoying levels during the day.

Transport part of the problem
Aircraft, motor vehicles and transportation systems are major sources of man-made noise in the world. For obvious reasons, it is in urban areas that noise is a major issue.

Some noise pollution can be eliminated through urban and traffic planning. But since commercial transport in many respects is the life blood of the economy, less noisy vehicles are called for.

Sound engineering
The current noise emission limit for heavy trucks in most parts of the world including the EU, India and South Korea is 80 decibels (dB).
The Volvo Group is continuously working to measure noise and vibration characteristics in engine and driveline components. Our sound engineers use both insulation and alternative design solutions to make everything from engines and transmissions to axles, fans and air intakes quieter. Our sound engineers also estimate that special trucks with embedded acoustic solutions and under driving conditions adapted to marshalling (speeds below 25 km/h) can fulfil specific sound demands in sensitive areas.

Next step: trailer and body

It doesn't stop at reducing noise from the engine. At speeds from 50 km/h for example, it is the vehicle's tires that make the noise rather than the driveline. This means that the entire vehicle, including tractor, superstructure, trailer and tires, must be worked on in order to efficiently eliminate noise at all speeds.

Reducing noise pollution

Truck filmed with an acoustic camera. The colour-coded sound map, here overlaid on an image of the vehicle, reveals sources of noise and their intensity

Promising city vehicle concept
In an EU project called FIDEUS, a Renault Midlum distribution truck underwent trials in the cities of Lyon and Barcelona, with a particular focus on night deliveries in the latter.

This truck featured, among other things, a low noise mode driver assistance system. Based on engine revs and vehicle speed, this mode was typically activated by the driver when entering Low Emission Zones (LEZ).

Through skilful engineering and improved sound-proofing materials, the pass by noise level was four times lower than an ordinary distribution vehicle.

Low-noise aircraft engines
Just like ground vehicles, aircrafts and their engines have noise limitation requirements. Research programs have been running for the last 20 years to reduce the noise at airports.

Volvo Aero is involved in what is called as the Noise Cluster, featuring several EU programs such as CoJen (Computation of Coaxial Jet Noise), aimed at developing and verifying technologies which will reduce fan and core noise from aircraft engines.