In a previous work, it was shown that attaching small weights to a membrane improves the sound insulation in a low-frequency range. This mechanism can be applied to a plate under the condition that the thickness of the plate is thin. This paper is concerned with the development of a sound-insulation board using the steel plate with additional weights, and result of a preliminary examination for the confirmation of mechanism, sound-insulation examination in reverberation rooms, and an application to practical noise control are shown. It is then verified that this material is useful for noise control in a low-frequency range.
