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 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: An elastic wave control element includes a piezoelectric material which is inserted into a propagation path for an elastic wave or installed in an oscillator to allow the elastic wave in a selected frequency to be damped, reflected, or transmitted. The piezoelectric material is provided with a pair of electrodes between which a negative capacitance circuit is connected to allow a loss factor of the negative capacitance circuit in a selected frequency or frequency band to be matched with a dielectric loss factor of the piezoelectric material.

Abstract: An elastic wave control element is inserted into a propagation path for an elastic wave or installed in an oscillator to allow the elastic wave in a selected frequency to be damped, reflected, or transmitted. A piezoelectric material 1 is provided with a pair of electrodes between which a negative capacitance circuit A is connected to allow a loss factor of the negative capacitance circuit A in a selected frequency or frequency band to be matched with a dielectric loss factor of the piezoelectric material 1.