It could be likened to the sounds of a creature or creatures in the woods on a dark night, but somewhat alien and not of this world. It could be from some avian or mammalian source, but it’s impossible to tell. It’s rhythmic and pulsating, but also distant, in short bursts of sound that recur regularly. The pitch of the sound is steady and unchanging, but the background sounds appear to be overtones of the pulsed pitches and occurring with less regularity. There’s a strange reverberance to the noise, as if the generator of this sound might be soon joined by others, still more distant at that moment.
I rather like these sounds and find their quality quite enthralling. The fact that they are constant in pitch and rhythm lend a certain comfort to listening to them which creates a certain, pleasant incongruity with the overall alien tone quality exhibited by the sounds. This duality is one that is often in my mind when hearing this sound.