What is a sound? What is noise? What is silence?
Sound is a vibration that brings us complex information. If I push my pen off this desk, you’ll know, even with your eyes closed, that a pen has fallen. You’ll be able to tell me that the desk is metallic and that we’re in a big room or in a really small space. A noise, in contrast, is a simple piece of information with a high sound level that prevents us from perceiving pertinent information. And silence? Silence is not the absence
of vibration. Besides, the absence of vibration doesn’t exist anywhere in the world. I believe that silence is
the absence of noise pollution.
Our distant ancestors heard the music of nature. Birdsong told them that such and such a place was a good habitat where they’d find water and food. Today, the city has become our habitat, and to regain this experience, we create indoor environments, auditoriums in which we listen to music. Clarinets and violins have become our birds. Cathedrals are among the last sanctuaries of silence in cities. There is a vital spiritual dimension, a reconnection to ourselves, in silence.
However it’s possible, if we do nothing, that today’s children will be the first generation in all of human history not to experience silence. If we are overcome by noise, we won’t survive. Therefore, we have to clean our sound environment, just like we’ve started to clean our polluted rivers. How? In Sweden, Quiet Parks is about to award the Quiet Urban Parks label to five parks in Stockholm. The city identified quiet areas and reduced the noise from transport around these parks to a minimum. And it was the Swedes themselves who decided what, for them, was an acceptable level of noise. It’s very different from one culture to another. We’re also working with the city of Taipei, in Taiwan. The Chinese have a deep relationship with nature and with silence, but Chinese cities are extremely noisy. They’re also going to have to decide what level of noise they want to accept in a Quiet Urban Park. Musician John Cage says: “we are what we hear”. If the French decide to develop these quiet areas in their cities, who knows what they’ll choose to hear?
Road travel accounts for 80% of the noise to which citizens are exposed, add to this noise pollution from construction sites in growing cities. For RATP Group, reducing these impacts is a key factor for improving health and well-being for everyone. With regard to transport, RATP has identified noise black spots on the 143 kilometres of overhead sections in its network (metro, RER, tram, and Orlyval) and has taken corrective measures.
It also strengthens its requirements on internal and external noise pollution levels with each upgrade of rolling stock. Lastly, phasing out diesel buses in the Paris fleet and that of its inner suburbs is synonymous with reducing noise.
In order to minimise the impact of sounds and vibrations for its passengers, local residents, and employees, RATP Group is implementing measures to prevent and/or reduce these disturbances, while organising studies on acoustical and vibrational impact and concept designs for all urban projects. The construction works for the future transport network, managed by the Société du Grand Paris, which greatly impact local residents and communities, are being carried out with a constant effort to reduce their impact. For each project (stations and maintenance projects), the construction methods, particularly the choice of a slab-covered or open-top tunnel, have been determined taking particular account of noise issues.