At the beach, the wind was blowing the sand, and those grains of sand were rubbing against each other in a big way, making a dense flowing sound. The sound is so gentle that one would think that the tiny grains of sand are on a journey of their own. When the wind blows through the trees, the swaying trees will make a “cackling” sound inside, which is not the rustling of the leaves, but the sound of the trunk from the inside, like a natural phenomenon of the trees struggling inside. Finally, there is the sound of a heartbeat in a quiet environment. In the extreme silence, the heartbeat is very clear, strong and rhythmic, as if it were the only response of the body in this silent space!