Trees and wind combine at times to create some remarkably worthwhile sonic results. These two are my favorite examples of this from my wanderings in the Patagonia.The first is of a tree that was growing above the roof of a hostel in El Calafate - or upon the roof, I couldn't be sure which. As the wind blew above, the thin branches and their leaves made a cacophonous dragging sound over the top of a sheet of greenhouse plastic. Not the most pleasant sound for a hungover morning in the common area.[audio:fieldrecording/treescrape.MP3]The second is what I believe were two guindo trees that had grown into each other over time, off the trail to Martial Glaciar from Ushuaia. Where they intersected, one had a stunted branch that, over time, chiseled away into the second in such a way that their unending collisions sharpened the stub. The result is an unending series of squeals, knocks, and rattles as the two move by the wind that tugs at their canopies above.[audio:fieldrecording/treesqueakstereo.mp3]This recording is particularly interesting when seen through spectral frequency. Such a chart composes time over the x-axis, and frequency (or pitch) on the y-axis, and much like a temperature map, colors the chart bright orange at points of high volume down to a dark purple in areas of low volume.The squeals often change rapidly and vibrantly in pitch. Here's an example of two such occurrences. This first image shows a rise in frequency, a gap in the sound, and a more drawn out drop in frequency as the trees part. The second image goes up and down in pitch also, but in a much quicker stretch of time.
I'm beginning to feel a bit overdone here, but in case you want some more, here's three more images of tree squealing. The stretches of narrow vertical lines are the creaking sounds. The final image is a mapping of sound from about 6:32 to 6:34.
