Usually, after a fresh snowfall, we often walk outside to play in that new snow… make a snowman or even shovel. But the next time you step foot outside your house after it snows, be sure to stop and listen… you won’t hear much.
Fresh snowfall absorbs more sound making our environment sound quieter. After that snow melts or crusts over, the sound is back to normal.
But let’s break down the science behind why this is happening. When you have fresh, individual snowflakes… there is more air in between them. The snow is fluffier and porous, which absorbs sound. Much like foam found in audio booths or the porous material you find on the walls of theaters, gymnasiums, and even tv studios. That material is designed to minimize sound. The fresh snow does the exact same thing
When the snow is melted or crusted over from melting and refreezing, it’s obviously not as fluffy and porous. It’s not in snowflake form with air in-between anymore. The sound bounces back off. Our environment is at more of a normal sound level with melted snow.
Another cold-weather aspect to sound is that it doesn’t travel as well when the air is frigid. In fact, sound at 10 degrees will travel at 724 mph. That same sound in 80-degree weather will travel at 776 mph. Cold air is denser so the sound has a harder time traveling than if it were in a warmer air mass.
To make your own speed calculations with air temperatures and sound, click here: https://www.weather.gov/epz/wxcalc_speedofsound