Comment by Tanoc

This is something I noticed as a kid. We had a creek in our backyard, which,depending on the temperature the water would be louder or quieter. This annoyed our dog, which after a number of times caused me to notice. Running water is louder and much more sharp when it's cold out, and quieter and muffled when it's hot out. In the same way sounds are louder in a colder environment because there's already a low level of ambient energy contained in the air and so the energy disperses much more readily but dissipates much more quickly. Essentially a difference between a quick "crack" and a lingering "whump" in terms of auditory impact. This effect also propagates to solid materials, as cold metals and ceramics transmit sound better than warm ceramics or metals. A church bell quite literally is louder on a cold winter's day.