Abstract
As a lightweight and low-cost noise reduction countermeasure, the author has developed a system to reduce the transmitted noise caused through panels by fixing noise insulation panels consisting of thin plates, piezoelectric materials and control circuits. In the case where an inductance circuit is used as a control circuit, a resonant circuit is made between capacitor of the piezoelectric material and the inductance circuit, and the transmitted noise reduced in range near the resonant frequency. This paper has described a way to spread the frequency range of control by double layer noise insulation panels with piezoelectric material. We clarified the influence given in the noise reduction effect of an air layer between upper and lower panels by the experiment.
