A light shielding structure of an optical device includes outer and inner annular members which move relative to each other in an axial direction, small and large diameter outer peripheral portions formed on the inner annular member, and a light shielding ring positioned inside the outer annular member and supported thereby. Multiple pieces of audio content data used as material data are prepared in advance in a material data storage device 31. Therefore, it can be used as the therapeutics or functional health food for treating and preventing inflammatory, allergic and asthmatic disease.