Embodiments of the present disclosure provide a diffusion muffling device, a diffusion resonance muffling device, a full-frequency diffusion muffling device, a muffling system for a ventilation channel, and a muffling method using the same, which include a plurality of diffusion muffling units disposed in the ventilation extension direction of the ventilation channel, wherein the plurality of diffusion muffling units are arranged in parallel in a direction with a predetermined angle between the direction and the ventilation extension direction of the ventilation channel, and a muffling passage is formed between each two adjacent diffusion muffling units, wherein each of the diffusion muffling units includes at least one diffuser, and each diffuser includes a plurality of convex portions so that sound waves entering the muffling passage are reflected multiple times in the muffling passage by the plurality of convex portions and then sound is attenuated. In the present disclosure, the diffusers are disposed to diffuse and reflect sound waves, so that the sound is attenuated in a long and narrow passage by multiple times of reflections of the sound waves, thereby improving the low-frequency sound muffling performance in the ventilation channel so as to effectively achieve an effect of sound muffling and noise reduction in ventilation.

A noise abating wall including piers with integral column members, columns each including two laterally extending wing walls, and a spandrel panel. The piers are secured in spaced ground holes with column members extending vertically from the pier securing the columns in a vertical orientation with the wing wall outer sides having a selected spacing from one wing wall of an adjacent column. The spandrel panels are wider than the selected spacing of wing walls of adjacent columns whereby the spandrel panel sides overlap the sides of adjacent wing walls. First connectors on the spandrel panel front face adjacent both of the panel opposite sides and second connectors on the wing wall rear faces adjacent the wing wall outer sides connect together to secure the overlapping walls and spandrel panels in substantially face to face contact.

A noise abating wall including piers with integral column members, columns each including two laterally extending wing walls, and a spandrel panel. The piers are secured in spaced ground holes with column members extending vertically from the pier securing the columns in a vertical orientation with the wing wall outer sides having a selected spacing from one wing wall of an adjacent column. The spandrel panels are wider than the selected spacing of wing walls of adjacent columns whereby the spandrel panel sides overlap the sides of adjacent wing walls. First connectors on the spandrel panel front face adjacent both of the panel opposite sides and second connectors on the wing wall rear faces adjacent the wing wall outer sides connect together to secure the overlapping walls and spandrel panels in substantially face to face contact.

A sprocket damping assembly for a sprocket wheel of a track-type work machine may include an annular damping ring having an annular retention device. The damping ring may include a ring body section having a ring body section radial thickness, and a retention groove section integrally formed at an outboard side of the ring body section. The retention groove section may have a retention groove section axial width and a retention groove section radial thickness. The retention device may have a retention device axial width that is less than or equal to the retention groove section axial width. The retention device is disposed on the retention groove section when the damping ring is disposed on a sprocket drum outer surface of the sprocket wheel to retain the sprocket damping assembly. The retention groove section radial thickness may be less than the ring body section radial thickness.

A sprocket damping assembly for a sprocket wheel of a track-type work machine may include an annular damping ring having an annular retention device. The damping ring may include a ring body section having a ring body section radial thickness, and a retention groove section integrally formed at an outboard side of the ring body section. The retention groove section may have a retention groove section axial width and a retention groove section radial thickness. The retention device may have a retention device axial width that is less than or equal to the retention groove section axial width. The retention device is disposed on the retention groove section when the damping ring is disposed on a sprocket drum outer surface of the sprocket wheel to retain the sprocket damping assembly. The retention groove section radial thickness may be less than the ring body section radial thickness.

In a soundproof member 10 including a polyurethane foam 11 and disposed apart from an engine E on a vehicle interior side of a dash panel 50 partitioning a space into an engine room having the engine E as a sound source and a vehicle interior, the polyurethane foam 11 has a surface layer 12 on at least a part of the surface thereof, a one side surface of the polyurethane foam 11 directly facing the vehicle interior side of the dash panel 50 has at least a surface layer 12A in an open cell state or a core, and a surface layer 12B of the other side surface opposite to the one side surface is a surface layer in a closed cell state.

In a soundproof member 10 including a polyurethane foam 11 and disposed apart from an engine E on a vehicle interior side of a dash panel 50 partitioning a space into an engine room having the engine E as a sound source and a vehicle interior, the polyurethane foam 11 has a surface layer 12 on at least a part of the surface thereof, a one side surface of the polyurethane foam 11 directly facing the vehicle interior side of the dash panel 50 has at least a surface layer 12A in an open cell state or a core, and a surface layer 12B of the other side surface opposite to the one side surface is a surface layer in a closed cell state.

Broadband acoustic absorbers may be capable providing good absorption performance between 0 and 3,000 Hz, and particularly below 1,000 Hz. Reeds may be incorporated in a single layer, multiple layers, or bundles. Such broadband acoustic absorbers may be applied for acoustic absorption in aircraft, spacecraft, residential and commercial buildings, vehicles, industrial environments, wind tunnels, or any other suitable environment or application where noise reduction is desired.

A baffle tile has a tile and a baffle. The tile is sized and shaped to be placed in a drop ceiling grid, and has a slot through its thickness. The body of the baffle is inserted into the slot in the tile so that the baffle hangs down from the tile. A pair of folding flaps are defined in an upper extent of the baffle by respective fold lines. The folding flaps are folded outwardly and down, such that they abut the upper surface of the tile. Folded down, the folding flaps define a locking slot. A locking member with features complementary to the locking slot is inserted into the locking slot to lock the folding flaps into position. The baffle itself may have additional fold lines so that it can be folded into its usable configuration from a flat sheet of material, without adhesives or fasteners.

A baffle tile has a tile and a baffle. The tile is sized and shaped to be placed in a drop ceiling grid, and has a slot through its thickness. The body of the baffle is inserted into the slot in the tile so that the baffle hangs down from the tile. A pair of folding flaps are defined in an upper extent of the baffle by respective fold lines. The folding flaps are folded outwardly and down, such that they abut the upper surface of the tile. Folded down, the folding flaps define a locking slot. A locking member with features complementary to the locking slot is inserted into the locking slot to lock the folding flaps into position. The baffle itself may have additional fold lines so that it can be folded into its usable configuration from a flat sheet of material, without adhesives or fasteners.