Abstract: First, sound absorbing plates made of a hard material are fixed to both side plates of shaped steel members extending upward from a sound insulation wall at intervals that are equal to arrangement spans of the shaped steel members. Then, sound absorbing members that have been formed into a predetermined shape and length are attached to outer surfaces of the sound insulation plates.

Abstract: A roof construction has vibration dampening ability and includes a body member in contact with a waffle-like surface of a moulded porous compressed fibrous web which is designed to have a self-supporting stability. The waffle-like surface exhibits an anisotropic air resistant structure.

Abstract: There is proposed the design of an absorber with the lowest reflection coefficient, especially between 30 and 150 Mhz where most of actual anechoic chambers exhibit problems. The absorber with optimized low frequency reflection comprises a a twisted pyramid having a length 11 and permittivity coefficients e1' and e1", a first layer adjacent the base of the pyramid having a width 12, and permittivity coefficients e2' and e2", and a second layer adjacent the first layer having a width 13, and permittivity coefficients e3' and e3", with 11 equal to 2.20 m (+/- 1 cm), 12 equal to 0.188 m (+/- 1 cm), 13 equal to 0.302 m (+/- 1 cm), ande1'=10 E (-0.370 LogF+1.005)(+/- 10%)e1"=-10 E (-0.484 LogF+1.012)(+/- 10%)e2'=10 E (-0.353 LogF+1.317)(+/- 10%)e2"=-10 E (-0.222 LogF+0.789)(+/- 10%)e'=10 E (-0.316 LogF+1.785)(+/- 10%)e"=-10 E (-0.598 LogF+2.347)(+/- 10%)in the range 30-150 Mhz.

Abstract: A tackable tile for mounting to a frame to provide a tackable surface to a wall having one or more of such tiles is disclosed. The tile includes a frame defining an open central portion, and a composite tackable member conforming to the perimetric shape of the frame and mounted in the open central portion thereof. The composite tackable memeber includes a resilient pierceable layer of material, and a layer of noise reducing acoustic material. The layer of pierceable material has a front and a rear side, and the acoustic material is adhered to the rear side of said resilient pierceable layer.

Abstract: A means of enhancing the acoustic attenuation and vibration damping of a material by embedding high characteristic acoustic impedance particles, low characteristic acoustic impedance particles, or both high and low characteristic acoustic impedance particles within the matrix of the material is disclosed. The mass of the resultant material may be very low while retaining excellent acoustic attenuation, vibration damping, and structural characteristics. When particles with mismatched characteristic acoustic impedances are embedded within the matrix of a material that can support shearing loads, propagating acoustic energy that encounters the particles of the instant invention is partially reflected in random directions. That is, the propagating energy is diffused. As the propagation vectors and modes of acoustic energy are effectively randomized, the probability of localized energy absorption and damping is increased.

Abstract: There is presented an underwater vehicle tailcone assembly including a ford flange, a first tubular sheath extending rearwardly from the forward flange, and elastomer material bonded to inner and outer surfaces of the first sheath to form a forward chamber wall. The assembly further includes an aft flange, a second tubular sheath extending forwardly from the aft flange, and elastomer material bonded to inner and outer surfaces of the second sheath to form an aft chamber wall. The assembly still further includes a rigid housing wall disposed between a rearward end of the forward chamber wall and a forward end of the aft chamber wall. The forward chamber wall, the housing wall, and the aft chamber wall form a continuous tailcone wall from a forward edge of the forward flange to a rearward edge of the aft flange.

Abstract: An apparatus and method are disclosed for reducing electromagnetic or acoustic energy scattered in both the near and more generalized vicinity of a source thereof by various phenomena including atmospheric and weather-related effects and diffraction at the top edge of heretofore known barriers. The apparatus includes a member configured for engagement with the top edge of a barrier, with the member having a patterned edge defining a plurality of portions jutting away from the top edge of the barrier and in a direction having a component toward the source, preferably substantially in a more or less horizontal plane with the top edge.

Abstract: A rapidly erectable, removable, reusable, and raisable acoustical wall system is provided that comprises a plurality of wall panels, each of which has opposing side edges which include a front edge and a back edge, a plurality of panel support posts having pairs of parallel flanges for receiving the side edges of the wall panels to form a wall, and a plurality of wedging members for forcefully securing the front side edges of the panels into an acoustically-obstructing engagement with the front flanges of the panel support posts. Wedge-receiving recesses are provided at the top and bottom of each of the back side edges of the panels, the top recesses of one panel being registrable with the bottom recesses of another panel when two panels are stacked between the same support posts.

Abstract: The panel shaped element finds application specifically for sound absorbing installations. It includes recesses proceeding from both its main surfaces which meet within the element and partially overlap each other. The recesses at one of the sides of the element have, thereby, shapes which differ from the shapes of the recesses at the other side thereof, such that the recesses form passages through the element. The recesses at the absorbing side are arranged in rows and the rows are arranged in a raster-like fashion. One of the sides of the element includes bores and the other side includes grooves. The bores are thereby arranged in rows parallel to the grooves and open into the grooves. Therefore, this panel shaped element can quite easily be selectively designed to cope with specific demands and circumstances by a changing of the relevant diameters.

Abstract: Wall coverings for anechoic chambers are disclosed having an array of lossy pyramid cone material mounted on multiple backing layers of absorbing material. The number of backing layers to be used, their physical dimension (thickness) and their material properties (conductivity and permittivity) are selected so as not to modify the high frequency (UHF) behavior of the pyramid structure, while at the same time providing a greatly reduced low frequency (VHF) reflection coefficient for the composite absorbing wall. The physical dimension and the material properties of each of the multiple backing layers are selected by a constrained nonlinear optimization data processing procedure or method. The optimization method utilizes known S parameters of the pyramid array, and either known properties of the backing layers, or constrained backing layer properties that are defined by the wall designer.

Abstract: A sound absorbing material is interposed between an outer perforated plate and an inner plate to constitute a sound absorbing body, which has a bottom wall portion extending generally vertically, a hood portion laterally bulging from the top of the bottom wall portion to assume a semi-circular cross-section, and a top wall portion extending from the hood portion to assume a gentle convex cross-section. A cap is attached to the end face of the top wall portion, and a fixing member is attached to a lower portion of the bottom wall portion to constitute a sound absorbing device. The two sound absorbing devices having the identical structure are fixed to the outer surfaces of an upper portion of an upright sound insulation wall through the fixing members so as to assume a symmetrical fixing posture. The caps of the two sound absorbing devices are connected by a connecting member.

Abstract: Soundproofing materials consisting essentially of zinc oxide whisker particles having a nucleus body and needle crystal portions extending radially from the central body in different plural directions. The materials may comprise a support material for supporting the zinc oxide whisker particles. Such support materials include inorganic materials such as metals, ceramics, glasses, cements, mortars and various fillers in the form of powder, flakes, fibers and the like, and organic materials such as resins, rubbers, waxes and the like. These materials are particularly suitable for sound insulation, sound proofing, vibration damping and vibration insulation.

Abstract: A sound absorptive material has powder particles having a sound absorption characteristics at a low frequency and generally supported in a vibratable state by a porous support, whereby the sound absorptive material can be increased in the sound absorption coefficient in the low frequency range while maintaining the absorptive material to be thin.

Abstract: A rapidly erectable, removable, reusable, and raisable acoustical wall system is provided that comprises a plurality of wall panels, each of which has opposing side edges which include a front edge and a back edge, a plurality of panel support posts having pairs of parallel flanges for receiving the side edges of the wall panels to form a wall, and a plurality of wedging members for forcefully securing the front side edges of the panels into an acoustically-obstructing engagement with the front flanges of the panel support posts. Wedge-receiving recesses are provided at the top and bottom of each of the back side edges of the panels, the top recesses of one panel being registrable with the bottom recesses of another panel when two panels are stacked between the same support posts.

Abstract: A sound wall for placement along a roadside for reducing the transmission of sound from a traffic area wherein the sound wall comprises a plurality of stiff, resilient containment members respectfully configured with the channel configuration and having an enclosed channel volume and continuous open side. Each channel volume is filled with a composite composition of rubber chips and binder compressed within the channel and substantially filling the channel volume. These containment members are stacked in nesting relationship to form a wall structure, with the open side being oriented toward the traffic area.

Abstract: A sound absorbing noise barrier panel has a precast reinforced concrete skin with a series of integral horizontal reinforcing ribs that provide a structurally strong panel that will resist wind loading and other requirements. The ribs form compartments on one surface of the panel skin which are filled with a sound absorbing material. A metal screen protective mesh is used to cover the compartments containing the sound absorbing material A decorative fabric is placed over the mesh and a protective decorative glass reinforced concrete lattice is used to finish the panel, resulting in a noise reduction coefficient of 0.95 to 1.0.

Abstract: An induction crucible furnace with a tiltable furnace body includes a crucible that is usually covered by an accessible furnace platform. The furnace platform is sonically uncoupled from the furnace body in an untilted normal position, in order to reduce sound intensity radiated by the furnace platform. Coupling elements, which effect a change of state between a very loose coupling or a complete uncoupling in the normal position and a close or rigid coupling in a tilted position of the furnace body, are provided between the furnace body and the furnace platform. The coupling elements can be spring elements, lug and bolt connections, lug and bolt and lug connections or lug and locking bolt connections.

Abstract: Composite soundproofing panels for applications in the automotive sector have a plastic layer bonded to at least one porous material layer. The plastic layer has a composition which contains a first elastomeric material, a high density filler material, a plasticizer and a second elastomeric material. The plastic layer is bonded to at least one self-supporting, premoldable layer of porous material while maintaining a constant thickness within +10%.

Abstract: A plurality of small blocks are disposed between an upper flexible layer and a more rigid and thicker layer. The blocks prevent the compression of portions of the carpet surrounding the area on which a load, such as the passengers feet, is placed. By preventing the compression of the major portion of the carpet, essentially unchanged carpet transmitivity characteristics are maintained.

Abstract: Material for providing acoustic protection against a source of noise, the material comprising a substrate and resonators, wherein said resonators formed on the substrate are constituted by thread-like and/or area-occupying composite elements whose structural characteristics (density, modulus of elasticity, shear modulus, damping factor, piezoelectric factor, etc. ...) and whose shape and/or size are selected to associate a predetermined resonant frequency with each resonator, and also to absorb the sound pressure energy from the noise source at said resonant frequency and dissipate it in the form of mechanical heat energy and/or electrical energy. The invention also relates to apparatus constituted by a wall including at least one layer of the above material.

Abstract: A device is provided preventing the transmission of sound, the device being fabricated of polymer composition and comprising a hollow core member formed of fiber-reinforced thermosetting resin, and at least outer member formed of unreinforced thermoplastic resin which is friction fit to the core member. The core member and outer members are preferably formed by pultrusion and extrusion, respectively. Adjacently disposed devices are connected together to form a fence-like barrier through which few or no sound waves are allowed to pass. This system is advantageously used to prevent sound waves emanating from a large transportation structure such as a highway, railroad track, or airport.

Abstract: A heat shield (1) includes a support layer (2) that is perforate only in predetermined partial areas (6, 7, 8) and comprises an insulation layer (3) that has a protective coating (4, 5) on both sides thereof. In particular, flange areas (6), attachment areas (8), and areas of bent or angular deformities (7) are free of perforations. A protective coating (5) on a side of the insulation layer facing the support layer has a thickness of less than 30 .mu.m and can be constructed of a thin aluminum foil or a sprayed or deposited metalized coating. Preferably, the protective coating has fine pores.

Abstract: A sound-absorbing multi-layer structure is disclosed comprising a structural part which is capable of oscillating and a loosely engaging damping sheet, which sheet comprises a flexible material and high material absorption factor and is made up of a heavy sheet with a viscoelastic support layer tightly connected thereto. The support layer comprises a plurality of angularly constructed support elements which are shaped and arranged so that together with the structure which can oscillate and the flexible heavy sheet they form a coherent labyrinth of hollow spaces with acoustically effective cavities.

Abstract: Soundproofing materials consisting essentially of zinc oxide whisker particles having a nucleus body and needle crystal portions extending radially from the central body in different plural directions. The materials may comprise a support material for supporting the zinc oxide whisker particles. Such support materials include inorganic materials such as metals, ceramics, glasses, cements, mortars and various fillers in the form of powder, flakes, fibers and the like, and organic materials such as resins, rubbers, waxes and the like. These materials are particularly suitable for sound insulation, sound proofing, vibration damping and vibration insulation.

Abstract: The panel with thermoacoustic insulation characteristics comprises an insulating layer made of foamed plastic material which has a succession of corrugated portions which are joined by reduced thickness portions. Metallic nets are associated with the opposite faces of the corrugated portions of the insulating layer and are mutually connected by transverse elements which pass through the insulating layer.

Abstract: An acoustic construction panel for use in the construction of walls, floors, or ceiling structures to improve the acoustical properties thereof, and a method of making that panel. The panel comprises a composition of natural wood fibers, paper and starch, and is absent of any chemical toxic products. The panel has a minimum thickness of about 3/4-inch, and an average density in the range of from about 15-lb/ft.sup.3 to 17-lb/ft.sup.3. A plurality of cavities are perforated on one surface of the panel to increase the acoustical surface properties of the panel. In the construction of the panel the wood pulp is directed into a holding tank for a predetermined period of time in order to expand the wood fibers, and further in which a composite mixture is produced by introducing into the wood pulp predetermined quantitites of starch and wax.

Abstract: What is provided is a system which would utilize a plurality of glare modules, constructed of a lightweight foam material, and that could be positioned spaced apart end to end, along the length of the highway median barrier. Each of the modules would be secured to the barrier by a pair of mounting rods firmly secured to the upper face of the barrier and slideably engagable into a pair of openings in the bottom of the barrier module. The barrier panel would then be secured to the mounting rods with a locking pin.

Abstract: A pyramidal cone absorber structure is equated to an effective absorbing layer model having effective permittivity and permeability properties. A Riccati equation, governing the coefficient of reflection of the effective absorbing layer is derived. A computer program solves the Ricatti equation for the coefficient of reflection using initial values of complex permittivity. Iterative solutions are then obtained using increasing values of complex permittivity until no further reduction in the maximum coefficient of reflection over a specified frequency range is obtained, thus indicating optimum performance of the pyramidal cone absorber structure for a given set of cone dimensions. Optimization of the pyramidal cone absorber structure may also be optimized for a fixed set of complex permittivity values by varying the cone length and backing layer dimensions while maintaining the sum of those two dimensions constant.

Abstract: A light-weight acoustical door is comprised of a wood frame separating and joining first and second panels and providing a space between the panels which filled with fibrous sound-absorbing material. Each panel is comprised of at least three layers, two of which are significantly more dense than the other layer. One of the dense layers may be made from a a weighted plastic sheet. One of the panels may have grooves formed in the inner face thereof.

Abstract: The present invention relates to an assembled sound-muffling thermal insulation board, and more particularly to a thermal insulation board having a surface board provided with plural pyramid bodies capable of greatly reducing the reflected sound wave going thereinto, and a sound-muffling thermal insulation layer mounted on the back face of the surface board, which is made from a styropor material and provided with plural fluffs to prevent convection of outdoor and indoor air with different temperatures whereby the hot air or cold air in an air-conditioned room will not escape and the energy is saved.

Abstract: The apparatus, for manufacturing building panels for construction walls with antiseismic and thermoacoustic insulation characteristics, includes a horizontal table for assembling a panel formed by at least one layer of insulating material and by a pair of metal grids associated with the opposite faces of said insulating layer, means for advancing said panel step by step to a station for inserting, cutting and welding connecting elements of said metal grids. The inserting and welding station includes means adapted to insert the connecting elements transversely to the insulating layer, lower welding means adapted to weld the connecting elements, which pass through the insulating layer, to the lower metal grid of the panel, means for cutting the connecting elements at the upper metal grid of the panel, and upper welding means adapted to weld the cut connecting elements to the upper metal grid of the panel.

Abstract: A sound absorbing pipe comprising a circumferential wall, open portions disposed at regular intervals in the circumferential wall having a predetermined area ratio and sound absorbing material disposed in a hollow formed in an interior portion of the pipe.

Abstract: An automotive headliner comprised of a laminate of double corrugated paperboard. Perforations in all the sheets of the laminate except the back paperboard sheet improve the acoustical performance of the liner. A vapor barrier on the back sheet prevents entry of moisture into the laminate from the roof, and a layer of sound dampening material on the front face of the laminate improves the sound absorption of the laminate. The front corrugation is larger than the back corrugation. When molding the laminate it is first moisturized, then heat molded. Heat is applied until the laminate has regained its rigidity.

Abstract: A concrete post assembly and method of mounting same. The post assembly is supported in upright position by an inground pier in which a plurality of anchor bolts are embedded with a portion of each bolt extending upwardly above the upper surface of the pier. The post assembly includes a concrete post and a base plate rigidly secured to the bottom of the post, the base plate having a plurality of holes located so as to register with upwardly extending anchor bolts. A nut is threaded onto each anchor bolt and the post assembly is mounted on the bolts with its base plate resting on the nuts which can then be adjusted to level the plate. A second set of nuts are threaded onto the anchor bolts and tightened against the upper surface of the base plate to lock the post assembly in mounted position.

Abstract: A noise silencer for highway is adapted to be stuffed in a joint gap formed in a highway. It has a rectangular casing and padding enclosed in the casing. The casing is provided with a vent hole adapted to be closed by a plug. Before mounting the noise silencer, air is firstly sucked out from the silencer through the vent hole to flatten the padding and the vent hole is plugged. After the silencer has been mounted, the vent hole is open to inflate the padding so that the silencer will be pressed against the opposite walls of the joint gap.

Abstract: A selectively transparent baffle means for controlling beam pattern dispel or direction, further comprising a plurality of parallel, vertically oriented, compliant tubes each of which attach to one of two header tubes at one end while the opposite ends are open to sea pressure. The headers provide air fill or vent.

Abstract: An acoustic wall for streets and parks and for garden-like designs consisting of several substantially U-shaped frame members arranged at a distance from one another, which frame members are connected among one another and have mats applied on their front and side surfaces. In order to substantially reduce the manufacture on location, the duration of setting up and the greening time on location, the acoustic wall consists of individual elements of which each has several U-shaped frame members which are secured at the ends of their long legs on a base. The base forms a rigid frame with fastening means for a lift for the lifting and transporting of the acoustic wall. One or several narrow-mesh mats are secured on the base, which mats prevent a falling out of material filled into the acoustic wall during transport.

Abstract: Adjustable packing strips (3, 4) are held on the inside of a carrying sheet (6) covered with sound-absorbing material (5), and are slidable by adjustment elements (7, 9), which can be actuated and fastened from the outside, within an adjustment chamber isolated against the sounds of a sound-emitting body (2) to project the packing strips beyond the peripheral edge (6A) of the carrying sheet (6).

Abstract: A multi-tubular acoustic absorber panel system suited particularly for use in open office environments or workspaces with unwanted echoes, excessive noise, or the need for enhanced acoustic privacy. The basic components of the system are a series of sound absorbent tubular members and a structure for holding the members in an array, creating a baffle which can be attached to wall or ceiling surfaces or, in the preferred embodiment, to a manufactured office partition. When installed, the system creates a lightweight, adaptable, highly absorbent enclosure, capable of significant reduction in unwanted noise and increase in acoustic privacy.

Abstract: A space divider of generally rectangular shape having perforated walls (1-8) with two opposite edges inturned to mate to form cavities (6) to hold acoustic bats (7) therebetween and including intersecting stiffeners (4-5) and means (16) to hold a pull-over fabric cover and including apertures (15-24) in end closures (11-22) to engage forming and locating means for the panels and for attaching shelving.

Abstract: A ductless noise attenuator is disclosed which includes a supply fitting mounted between an air conditioning unit and a recipient. The supply fitting blocks line-of-sight soundwaves using triangular-shaped protrusions on the inlet and outlet edges of a housing, and a diamond-shaped core which fits in the housing and has edges which extend to the space between the triangular-shaped edges of the inlet and outlet of the housing. The diamond-shaped core is composed of: two leading edges, which form a wedge with its point facing the housing inlet; and two trailing edges which is overlapped by the triangular protrusions of the housing. Finally, a return fitting conducts air back to the air conditioning unit while blocking line-of-sight soundwaves with a diagonal divider within a return housing. The design of the attenuator is intended to provide a minimum constriction on the airflow from the air conditioning unit, with a maximum of sound attenuation at audible frequencies by blocking line-of-sight soundwaves.

Abstract: A panel is provided for use in a sound absorbing wall structure. The panel includes a front of wood based material having perforations, a back parallel with the front and separated from the front. Sound absorbing material is positioned in engagement with the front within the space covering the perforations so that the panel absorbs sound directed at the perforated front of the panel by absorption in the material of the front as well as in the sound absorbing material.

Abstract: A sound barrier for use along vehicle pathways including a gabion, the gabion comprising a wire cage filled with sound absorbing material and ballast material; gabions in the potential path of vehicles leaving the pathway have resilient filler material for cushioning the impact of vehicles striking the gabion.

Abstract: A sound attenuating partition or door construction which includes outside rigid panels having significantly different thicknesses, a void being left between the panels, a sheet characterized as a limp mass loosely hung within the void, and grooves cut into an inner surface of at least one of the outside panels in order that the void serves as a sound absorbing anechoic chamber.

Abstract: The present invention is an acoustic panel having a porous layer and a generally rigid layer affixed to each other. The generally rigid layer includes at least one passageway opening on one side of the rigid layer and extending through the rigid layer to the porous layer. The porous layer is a fibrous material. The rigid layer is a concrete-type material, such as vermiculite-cement plaster. This acoustic panel further comprises a generally rigid planar surface positioned adjacent to the porous layer. This generally rigid planar surface can comprise an insulating layer affixed to the other side of the porous layer and a structural layer fastened to the insulating layer. The insulating layer is a polyurethane foam board. The structural layer is a particle board.

Abstract: A post and panel type noise barrier fence is formed of a plurality of concrete vertical posts or columns which have grooves to hold flat concrete panels between successive ones of the columns. The panels can have a stepped lower edge to accommodate elevational changes in the terrain. Also, certain of the columns have oppositely disposed recesses angled from each other so as to accommodate directional changes at the columns in the direction of the barrier fence.

Abstract: An acoustical ceiling tile is provided with a metal facing sheet covering at least one raised rib on the surface of the acoustical tile. The raised rib has two parallel sides and the facing sheet is made with two parallel edges having the ends thereof spaced apart a distance slightly less than the rib width. Consequently, the edges of the facing sheet will engage the edges of the rib and frictionally hold the facing sheet over the flat surface of the rib.The above structure will permit humidity and temperature to cause fluctuation in the dimensions of the base sheet containing the raised rib without resulting in any distortion of the metal facing sheet.

Abstract: The present invention relates to acoustically porous building materials which are produced by disposing an aggregate material on the surface of a dry-formed web comprising a fibrous material and an organic binder, and consolidating the composite material such that the aggregate material is embedded in the web. The resulting product is acoustically porous but, in one preferred embodiment, the embedding process provides a substantially planar surface which is relatively non-friable.

Abstract: A sound-absorbing element of films has adjacent, cup-shaped recesses in the orm of a grid. The bottom surfaces of the films which are to be exposed to the sound field may be excited into dissipative vibrations when sound is incident thereon. The upper edges of the cup-shaped recesses are jointly covered by another flat material web. The bottom surfaces of the cup-shaped recesses are subdivided into bases by one or more crimp-shaped recesses, the depth of which is appreciably smaller than the depth of the cup-shaped recesses. The sound-absorbing element may be used in building, underground and tunnel construction and in vehicle construction.

Abstract: A method of manufacturing a damped resonator acoustical panel in which a porous acoustical damping fabric and a resin impregnated open weave fabric are laid up and subjected to moulding by the application of heat and pressure thereto to cause a portion of the resin from the open weave fabric to impregnate the abutting portions of the acoustical damping fabric and bond the fabrics together. A film of an adhesive is then applied to the open weave fabric and heated by a hot gas stream until it reticulates. The bonded fabrics are then bonded to the edges of an open honeycomb core by means of the reticulated adhesive. A solid sheet is bonded to the other side of the honeycomb core in order to close the cells thereof.