Patent ID: 11749248

Abstract:
Provided is a soundproof structure that is small and light and can reduce a noise with a high specific frequency of a sound source at a plurality of frequencies at the same time. A soundproof structure includes a plate-like member in which at least one through-hole is formed, a membrane-like member that is disposed to face one surface of the plate-like member, and a support that is formed of a rigid body and supports the plate-like member and the membrane-like member, in which the membrane-like member is supported by the support so as to perform membrane vibration, in which a first space is provided between the plate-like member and the membrane-like member, in which a rear surface space is provided on a side opposite to the first space with the membrane-like member sandwiched therebetween, in which the membrane-like member, the support, and the rear surface space form a first sound absorbing portion that absorbs a sound by membrane vibration, in which the plate-like member having the through-hole, the support, the membrane-like member, and the first space form a second sound absorbing portion that absorbs a sound by Helmholtz resonance, and in which assuming that a fundamental frequency of the Helmholtz resonance in a case where the membrane-like member is regarded as the rigid body in the second sound absorbing portion is fh1 and a fundamental frequency of the membrane vibration of the second sound absorbing portion is denoted by fm1, fh1≥2×fm1 is satisfied.