Linda Moulton Howe will be on Coast to Coast AM tonight @11pm-2am. She has been researching these sounds.
Linda's website:
http://www.earthfiles.com/http://www.coasttocoastam.com/show/2012/02/23Clif High has talked with three people that have heard these sounds. One guy said he felt the vibration coming through the soles of his feet before he heard it. Another, a musician standing on a shoreline, said there was an edge to the sound versus the shoreline sounds (waves), it was not coming from the water. And they reported that the sound was different in person than what can be heard on the recorder.
Clif's interview:
http://www.sunskymysteries.com/The interview is on a loop cycle now when you go to the above site. I don't know when he will be replacing it with another interview.
And the rocks will cry out!