Abstract: It is an object of the present invention to provide a solid-borne sound reducing structure which is able to reduce solid-borne sound with a simple configuration, highly durable, and being less degraded. There is provided a solid-borne sound reducing structure (100) in which a surface plate part (1) including a gas ventilating part (1a) which allows gas to pass through along a thickness direction is disposed by means of an outer peripheral wall part (2) on a structure (200) that radiates noise while vibrating, so as to at least partially cover a surface (200a) of the structure (200). The surface plate part (1) is supported by the outer peripheral wall part (2) so as to be integrally vibrated with the surface (200a) of the structure (200). In addition, the outer peripheral wall part (2) supports the surface plate part (1) in such a manner that an internal gas chamber is formed between the surface (200a) of the structure (200) and the surface plate part (1).

Abstract: A double wall structure capable of suppressing an increase in a sound transmission amount with regard to sound with a specified frequency and stably exhibiting a sound insulation performance for sound with various frequencies is provided. A double wall structure 1 is assumed to be a door serving as a part of an automobile. The double wall structure 1 is provided with plate-like bodies 2 and 3 arranged in parallel and opposing to each other with leaving a predetermined distance. The plate-like bodies 2 and 3 are formed in a rectangular shape with one direction being slightly longer. Between the two plate-like bodies 2 and 3 opposing to each other is formed an internal chamber 4. Side plates 5 are provided so as to connect the plate-like bodies 2 and 3 to each other, and thereby the internal chamber 4 is almost closed.

Abstract: It is an object of the present invention to obtain the configuration in which sound transmission can be decreased and sound insulation property can be enhanced in a double wall structure as an automobile part such as a door, a hood, and a truck lid. In a double wall structure in which an internal space 4 is formed between facing plate-like bodies 2 and 3 and the internal space 4 is closed, at least one sound absorbing material 6 which reduces an air particle speed is provided at a position where the air particle speed is maximum in the internal space 4 or near the position. As the sound absorption material 6, a porous body, a plate-like body, a foil-like body, and a film-like body (including the material having many through holes) can be adopted. The sound absorbing material 6 is in contact with at least one of excitation-side plate-like body and radiation-side plate-like body in the facing plate-like bodies 2 and 3.

Abstract: A double-wall structure (1), comprising plate-like bodies (2) and (3) disposed oppositely to each other to form an inner room (4) therebetween, peripheral members (5) disposed so that the inner room (4) can be completely or approximately closed, and perforated plates (13) with a large number of holes (8) disposed between the plate-like bodies facing each other. The double-wall structure is characterized in that an air layer (A) is interposed between the perforated plates and the peripheral members. Thus, since the double-wall structure can suppress the deterioration of a sound reduction index for sound with specific frequencies, it can stably develop sound insulation performance for sound with the various frequencies.