Abstract: A sound insulation/absorption structure, a sound insulation/absorption device, and a structure having these applied thereto and a member constituting the same, are capable of insulating or absorbing sound by stiffness control. The sound insulation/absorption structure comprises a film member, such as a polymer film or metal foil, and a frame body having at least one annular opening, the film member being fixed to the frame body, the section of the film member surrounded by the frame body being of a curved shape such as a dome, wherein the resonance frequency of the in-plane stretching of this curved shape is set at a frequency equal to or higher than the audible frequency band, so as to insulate or absorb sound by the elastic force of the film. The film member may be replaced by an acrylic, polyethylene terephthalate or other plastic plate, an aluminum or other metal plate, or a veneer or other plate member, molded into a curved shape, such as a dome, a semi-cylinder and a cone.

Abstract: A structure for decreasing low frequency air vibrations, comprising a sound insulating floor, sound insulating sidewalls and a sound absorbing ceiling arranged so as to form an air chamber below and separate from the underside of an elevated road or railway bridge's traversed surface, thereby forming a space between the sound absorbing ceiling and the elevated bridge. The structure is very effective for decreasing the low frequency air vibration emanating from the structure of the elevated bridge and the low frequency air vibrations transmitted from the structural supports of the elevated bridge.