This is a top view of the same Chladni plate shown in the previous page. From this viewpoint it is easier to see how the bouncing grains of sand move to the nodes where the plate is not moving.

As the frequency increases the pitch of the sound also increases, but the sound is loud only for standing waves that fit the plate. At the end of the video the outer edge of the plate is vibrating a lot and so there is no sand there. Proceeding toward the center of the plate there is a node with lots of sand, then another area of strong vibration, another, thinner node, another area of vibration, another node, and then a vibrating area near the center of the plate. Notice that the circular plate has circular nodes, and that the amplitude of vibration depends on the distance from the center of the plate.