[Hammock Parties]

Originally Posted by arrwheader

Sound does, indeed, "carry better" when air is calm and bitterly cold. Sound normally travels outward in all directions from its source. However, when air is bitterly cold, a strong "temperature inversion" (warm air above cold air) exists, and this resists the usual upward movement of sound. Sound waves heading up tend to reflect off the sharp temperature (and density) boundary that exists between the cold and warm layers, and sound waves return to the surface--often at a considerable distance from their source.

Frigid air is also extremely dense--sound waves travel well in such air. And, with no wind, background noise is at a minimum. Distant sounds can be clearly heard.