Some says that it is The sound of Our Earth. If you go to Tiruchendur Temple there will be a Hole on the Wall facing the sea. If you observe your Ears in to that hole you can Feel Very Clearly The Om Karam via the Sea Waves. We can observe Clearly that The sound will be like a Saint Chanting Ohm on the other side... Has any one Experienced This ? I have experienced it many times in my life..