SOUND ABSORBING PANEL, AND SOUND ABSORPTION METHOD AND ACOUSTIC IMPROVEMENT METHOD

PROBLEM TO BE SOLVED: To provide a sound absorbing panel which can improve sound absorbency for sound waves in a low frequency region.SOLUTION: A plate 12 having one or more opening parts 12a is laminated on one surface of a fiber sound absorbing layer 13 and a plate-shaped honeycomb structure 14 is laminated on the other surface of the fiber sound absorbing layer 13 to make a sound absorbing panel 11. An area ratio of the opening parts 12a may be approximately 10-80% based on the total area of the plate 12. The plate 12 may have a plurality of opening parts, and an average area of the opening parts may be approximately 5-2,500 cm. An average thickness of the plate 12 may be 1-15 mm. A ratio of the average thickness of the plate 12 to that of the fiber sound absorbing layer 13 may be 2/1 to 1/10. The plate 12 may be formed of a woody material. The fiber sound absorbing layer 13 may be formed of a plate-shaped nonwoven fiber structure in which fiber is fixed by fusion of wet heat bondable fiber.