“Snow and sound
The characteristics and age of snow can affect how sound waves travel, dampening them in some cases, or enhancing them in others. For instance, people often notice how sound changes after a fresh snowfall. When the ground has a thick layer of fresh, fluffy snow, sound waves are readily absorbed at the snow surface, dampening sound. However, time and weather conditions may change the snow surface. If the surface melts and refreezes, the snow becomes smooth and hard. Then the surface will help reflect sound waves. Sounds may seem clearer and travel farther under these circumstances.
Snow may also crunch and creak. A layer of snow is made up of many tiny ice grains surrounded by air and when you step on it, you compress the grains. As the snow compresses, the ice grains rub against each other. This creates friction or resistance; the lower the temperature, the greater the friction between the grains of ice. The sudden squashing of the snow at lower temperatures produces the familiar creaking or crunching sound. At higher temperatures, closer to melting, this friction is reduced to the point where the sliding of the grains against each other produces little or no noise. It is difficult to say at what temperature the snow starts to crunch, but the colder the snow, the louder the crunch.”