OK, this question is not your usual one: Last night while hiking solo from the mountains back to my car at the mountain/desert interface (Lone Pine, CA), I had a rather bizarre -- and downright spooky -- experience.
The last half-mile of my return was in total darkness, which wasn't a problem since I had prepared for that unintended possibility. Partway into that last portion of the hike, with my LED flashlight piercing the remote, desert darkness, I began hearing a slow, distinct and loud "breathing" sound, both inhaling and exhaling, which became more pronounced the closer I got to my car. The source seemed to be perhaps a couple hundred feet away. I'll skip the whole middle part which had a Blair Witch vibe to it -- at one point I froze in my tracks in the darkness for a minute or two, pondering what to do. Ultimately I realized the sound was coming from a large, steel, high-voltage power transmission tower. I had noticed earlier that that particular tower had been louder than the others in the daylight, buzzing and cracking, but nothing more than that.
The loud, rhythmic "breathing" noise began after the sun-baked tower began cooling down, with a modest 5 MPH wind present. It sounded EXACTLY like an animal slowly "breathing." I'm familiar with the corona discharge effect of such towers. But anyone have any insight into the pitch-black desert "breathing" phenomenon?