Why does snow make sounds seem quieter?
Short answer
Fresh snow contains many small air spaces that absorb some sound. This reduces reflections from the ground, so nearby sounds can seem softer and more distant.
How it works
Sound travels as vibrations in the air and reflects from surfaces such as the ground and walls. A layer of fresh snow is a porous mixture of snow grains and air. When sound enters those spaces, the air moves in small, resisted motions and some of the sound energy is converted into heat.
Less sound is then reflected back toward us. Snow that has been packed down or covered by a hard icy crust can behave differently, because its surface has fewer open spaces and may reflect more sound.
Key point
Snow does not make every sound disappear. Wind, traffic, buildings, the amount of snow, and whether the snow is fresh or compacted all affect how quiet the scene feels.