The Sound of Sand Dunes

For these booming sand dunes to exist requires a very specific set of circumstances. To get the soundet you need it, and yo, have to have a very large sand dune. What we really think happens is that over the course the summer, the dune really dries out. And that when you've got just dry sand grains, that if you push on one, kind of sending a pulse intoto the sand they just knock against each other.