Why does sound travel better on some days than others?
It is an urban legend to believe that in the winter, the air being colder and therefore denser, carry better the sounds. It is true that colder air is denser and that sound waves move faster in colder air but our perception in decibels of the sound attenuation is not sensible to that. On the other hand, aircraft are and that’s why airliners often measure their speed not in mph but in Mach, i.e. a fraction of the speed of sound for that altitude and temperature. What defines how good we can hear a distant sound is: 1) The actual acoustic of the place. Obstacles prevent the sound propagation. Open sea water is often the best sound carrier. 2) Interferences. The wind is the greatest one. Imagine you thrown a stone in the water of a lake that is perfectly calm. The circles of wavelets will travel very far. Imagine now that you throw that stone in a fast moving river on a windy day … do you see the difference?
