Schumann wave itself does not make any sound, it is not directly acting on the sound or video products to improve the quality of sound or vision. It's working on the space environment, make the people's physical and mental get relaxed, improve the body's perception of sound and images, improve the human body health and working efficiency, it also has a good effect on insomnia, mental strain and so on. For more information please Google "Schumann Resonance".
eBay