TURNING NOISE INTO SOUND
A change of perspectives can work wonders. In places where noise levels cannot be reduced, new urban planning concepts are helping to make city life more pleasant. Not far from Daimler headquarters at Sindelfingen is the town of Böblingen, where the company conducts its research and advance development projects. Here, a sound installation at a busy central intersection filters the noise from passing vehicles.
Fountains positioned along the intersection well up audibly whenever the traffic lights are green. The result is that the pass-by noise, which can reach up to 80 decibels, recedes into the background. If pedestrians have a green light, the fountains murmur softly and the town centre turns wonderfully quiet for a moment.
From a global standpoint, Böblingen’s Elbenplatz square may only be a tiny intersection. But vehicle noise can be a real problem for people living in towns and cities of all sizes. Böblingen therefore offers a good example of how noise perception can be actively influenced in busy urban centres.
ELECTRIC VEHICLES FOR QUIETER ROADS
As electric cars increase in popularity, there is growing hope that they will help to reduce noise. But according to the German Federal Environment Agency (UBA), that will only be the case up to a point: below 25 km/h, electric cars are indeed quieter than their internal-combustion counterparts. But at higher speeds, tyre noise and wind turbulence become responsible for the roadside concerto – just like with regular cars.
The UBA believes that other types of vehicle – from trucks, buses and waste collection vehicles to mopeds and motorcycles – have a bigger part to play in bringing down noise levels. If these have an electric drive, they run far more quietly than before. The critical factor, however, is the proportion of the fleet accounted for by electric vehicles – and it will be a long time yet before this becomes significant.
Ironically, electric vehicles can sometimes be too quiet: For safety reasons, some countries require them to be fitted with noise generators that are activated primarily when the car is travelling at low speeds – this is to warn pedestrians who might otherwise not hear them coming.