Cymatics and crop circles

We all no most Crop circles are man made but there is a 20%
that remain to pristine to untouched I reckon its all down to
acoustics.... have to admit not heard any chants in my travels
in crop circle country actually not seen any one ever hoaxing one
either

interesting video and THis is what causes the truly good formations in
my opinion

https://www.youtube.com/watch?feature=player_embedded&v=Yw13EAX3cZk#!