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At a friend's home on the top of a hill one can often hear howling winds with the frequency rising and falling in parallel to the strength of the wind's force.

When one blows over a mouth of a jug or blows a whistle or plays a musical instrument like a flute or recorder, the force can have a small effect of say a few percent on frequency which can be understood as some nonlinearity.

But in the case of the howling wind frequency seems to be roughly linearly proportional or at least close; I've heard a continuous howl change by almost one octave (a factor of 2) in a single run.

Are howling winds produced by at least an approximately resonant process? If so, is the resonant volume determined by both geometry and the speed of the wind?

A quick search through YouTube will find numerous examples of the sound: https://www.youtube.com/results?search_query=howling+wind

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When sound is produced by the wind blowing past objects in its way, the usual mechanism is called vortex shedding and was studied by Von Karman in the late 1940s. In his model, sound waves are produced when the wind blowing past (for example) a wire toggles between blowing over the upper surface and the lower surface. This cyclic excitation gets coupled to the object, causing it to vibrate. If the vortex shedding frequency is close to a resonant mode of the object, then the amplitude of the object's oscillation will become large. Fast wind produces higher frequencies, but the size of the object also affects the pitch.

See also links in @KeithMcClary's comment

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    $\begingroup$ Thanks for this; will edit answer to point to your comment. -NN $\endgroup$ Jan 27, 2020 at 18:14

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