Did anything come of this research?
I am developing a 300Hz to 15 kHz VLF receiver to listen to whistlers, the dawn chorus, etc.
(That's not my recording by the way!)
But it's occurred to me that VLF baseline recordings made miles away from standing stones (and power cables!) and then around standing stones, both compared and displayed using software in the video may be revealing.
Did anyone contact the VLF yahoo group I suggested?