Toward Ecosophy

I believe you've wrote before on this blog that, although definitely belonging to the psychotic end of the New Thought spectrum, H.J. Gardener published a lot of valuable exercises, mostly of Rosicrucian origin. One of those is the Sound of Universe exercise (described in detail on pp.22-23 of Streamline Minds and in multiple of his other monographs, the short version is closing your eyes, plugging your ears by gently pressing on the bit of cartilage in front of ear canal and focusing on the "white noise" in your right ear), which I've been trying out in the last few weeks. Do you happen to know where it came from and what it is originally supposed to do? So far in my experience it works as a relaxation technique, and, for me at least, it seems to work better than conventional progressive muscle relaxation methods.