Sergey Baldenkov mentioned he might stop over to talk about his amazing work with sound and vibration. Sergey is a Russian researcher who is able to demonstrate how Ed may have been able to accomplish at least some of what he did using the power of sound.
Most of his work is in Russian, but thankfully we have Gardner and Charlie to help us overcome any language barriers.
BTW i am thinking about the "melting of stones" with frequencies (sound or so) for a looong time already... Let's read what Sergey has to say about that.
...by "melting" i mean softening
May I suggest to start out small ,
I borrowed this photo from Sergey's site.
Could Ed have structured Coral Castle (and even perhaps his generator) to mimic the human ear?