Image © Gabriel Niquet

A walk in the fresh snow is a real pleasure ! The immaculate whiteness of the landscape, the muffled sound of footsteps on the trails... Everything seems so calm. But why the silence after a snowfall?   

Before reaching our ears, sound, or rather sound waves, encounter many surfaces (a wall, a tree, the snow). However, not all surfaces reflect sound in the same way. A hard surface, such as a road, reflects sound very well, retaining almost all its energy. Conversely, other surfaces absorb more sound than they reflect. These include fibrous materials such as rock wool, or porous materials such as foam. Fresh snow could be classed as a porous surface, as it is composed of more air than snowflakes. Sound penetrates the snow and has to expend a lot of energy to circulate between all those snowflakes, so it comes back with little energy to your ears. The result: fresh snow acts like soundproofing panels, giving us the sensation of a cocoon of white silence !    

• Quand la météo joue avec le son : https://www.meteo.nc/8-actualites/562-quand-la-meteo-joue-avec-le-son 

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• Pourquoi ce silence quand il neige? : https://science.lu/fr/les-pouvoirs-neige/pourquoi-ce-silence-quand-il-neige 

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• On entend un peu plus les sons en hiver, mais pourquoi ? https://www.radiofrance.fr/francebleu/podcasts/ramene-ta-science/on-entend-un-peu-plus-les-sons-en-hiver-mais-pourquoi-7920043 

• Un livre : Histoire naturelle du silence / Jérôme Sueur ; préface de Gilles Boeuf