Weatherwatch: Can you really hear the wind?

Some would argue airflow is silent, and that only the objects in its way give rise to vortex shedding or soughThe evocative sound of wind in the trees, called psithurism or sough, occurs when the smooth, "laminar" flow of air becomes turbulent around branches, twigs and leaves. The different scales of obstruction give rise to a mix of different frequencies of sound, resulting in something like white noise. Wind through pine trees is higher pitched because of the smaller size of pine needles, making a hissing or whispering sound.When indoors you may sometimes hear the wind howling. That sound is the airflow interacting with the sharp edges, gaps and openings of buildings, producing a note in the same way as blowing over the top of an empty bottle does. These are known as Aeolian tones after Aeolus, the Greek god of winds. Continue reading...