What Makes the Sea Roar?
The roar of the sea is a movement of the sea which causes the same kind of air waves or sound waves that you make when you shout, excepting that, of course, the vibrations do not occur so quickly in the sea and, therefore, the sound produced is a low sound. It is no different in any sense than the same noise would be if the same air waves could be produced on the land away from the water.