Abstract: An acoustical absorbing material including a plurality of porous sheets and a plurality of high density sheets alternately superposed one over another and held together with contact with one another. At least one of the high density sheets is formed therein with one or more through-holes. The acoustical absorbing material of the above-mentioned construction exhibits a good acoustical absorption performance in a wide frequency range even if its thickness is not varied, and is effective in shutting off noises produced by electronic equipment, such as a computer.

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: An improved ceiling panel especially useful in mobile residential or commercial structures is provided wherein said ceiling panel has on one surface (usually the back surface) a moisture barrier comprising a cured coating of an aqueous emulsion of slack wax, an emulsifier of triethanolamine and stearic acid, and silicone.

Abstract: A plate-component (1) which can be used for airborne-sound insulation has chambers (5, 6) filled with a pulverulent or granular, e.g. metallic material, whose chamber walls (2, 3, 4) at least partly are formed by a flexible material. Chambers (5, 6) are small in the vertical direction, but in the horizontal direction can form long channels. This construction not only leads to an increase in the sound insulation of a board joined to component 1 corresponding to an increase in the weight per unit area, but it is also possible to prevent coincidence breakdowns in the range 100-3000 Hz.

Abstract: An acoustical control media includes an air impervious septum adjacent which there is positioned a relatively thick layer of low density filler material on the outside of which there is provided a relatively thin panel of medium density perforated material. The acoustical media so formed can be used in acoustical panels employed to separate work areas in an office and in such applications decorative coverings can be provided over the perforated layer. The structure so formed provides improved broad bandwidth absorption of acoustical energy.

Abstract: An acoustical wall panel includes an elongated sound absorbent board faced with a needle-punched non-woven fabric provided with a woven scrim backing and having linear ribs extending longitudinally of the panel. Such panels are mounted by generally H-shaped splines concealed by the panels. The lofted texture of the fabric and the linear ribs help conceal a seam between two panels.

Abstract: A panel for sound insulation of vehicles or other devices is described which is constructed of a fabric of autogenously and chemically bonded, matted polyester fibers having fine surface pores. The fabric is shaped by compression so that it has a thickness of 1 to 3 mm. and exhibits an acoustical impedance of about 30 to about 100 Rayl.

Abstract: The invention is directed to a wallboard structure which is first composed of a base sheet having a dense upper surface region. Over the dense surface region there is placed a vinyl sheet. Perforations are placed through the vinyl sheet and through the dense surface region and partly into the base region so there is formed an acoustical vinyl faced wallboard.

Abstract: A sound-damping mat or drape comprises a flexible layer (5) having distributed therein particles (5) of a higher specific gravity than the material of the flexible layer. The flexible layer comprises a material having open pores and the pores are filled over at least a part of the thickness of the layer with said particles. The particles are bound to each other and to the defining walls of the pores. The mat or drape is preferably manufactured by vibrating the heavy particles down into the pores of the porous flexible layer, whereafter a binder is sprayed over the surface of the layer.

Abstract: A sound deadening material is obtained with a very high loading of sound damping materials such as barium sulfate, calcium carbonate or metal powders. These materials are mixed with water and are bound together by adding a water-miscible isocyanate-terminated prepolymer which reacts with the water to form a cross-linked binder.

Abstract: This invention pertains to asphaltic sheet sound deadener for use as a vibration damping medium, which can be bonded in place without excessive sag or flow by subjecting the material to 250.degree.-400.degree. F. The main use of this material is in the automotive field, but may be used in other areas such as the appliance and furniture industries. The melt flow properties of the deadener are controlled by the use of ground mica.

Abstract: The present invention relates to a noise shield including a massive shield wall and an attachable absorbent unit on the shield wall. Thus the noise shield can be used with the absorbent unit along the parts of the road where you do not want reflections of the noise which you want to reduce and without absorbent unit along the parts of the road where you just want a reduction of the noise.The noise shield is constructed of posts, which are anchored in the ground. Between these posts are mounted support beams. The shield wall consists of shield modules. Each shield module consists of a plank panel, which is mounted on a frame, the plank panel functioning to reduce noise. Furthermore, into the cavity of each shield module; an absorbent unit can be inserted therein, which includes a frame and a panel. A noise shield can be constructed along a part of a road by anchoring the posts in the ground, mounting the support beams thereon and placing the prefabricated shield modules between these posts and support beams.

Abstract: A method of making a panel for installation in the high velocity air flow region of an engine nacelle and other applications requiring sound absorbing material and increased air frame strength. The panel utilizes a single layer of either a metallic or nonmetallic cellular core with a solid or perforated septum disposed internally therein. The septum may have a planar or nonplanar configuration within the individual cells of the core thereby providing means for reducing the noise level of various sound frequencies created by a jet engine or any other sound producing devices for that matter. The planar or nonplanar septum provides structural stabilization and/or vibration dampening to a bonded sandwich assembly. The panel may also be used in strengthening air frame construction and other applications besides sound attenuating panels.

Abstract: A method for producing an acoustical ceiling tile or panel faced with a distortion free decorative thin plastic film is accomplished by first embossing the acoustical base to form a picture frame surrounding a recessed area, stretching the thin decorative plastic film over the picture frame portion and adhesively securing the film to the side and/or back of the acoustical base and subsequenytly heat shrinking the film to produce a distortion free decorative surface.

Abstract: A multi-layer acoustic lining is of the type having core compartments rendered effective as Helmholtz resonators by means of resonator necks projecting from the core facing layer into the core compartments. In order to broaden the frequency response, those ends of the resonator necks which project into the core compartments are bevelled so as to give the necks a less well defined length. The acoustic lining is particularly for application to the jet pipe or fan duct of a turbofan aeroengine.

Abstract: A flexible acoustical wall covering, method of making same, and wall panel employing same are provided wherein such wall covering is comprised of a laminated construction comprised of a substrate and an outer layer bonded against the substrate with the outer layer having a roughened outside surface defined by projections and indentations which serve as miniature sound baffles and a plurality of spaced openings in and disposed perpendicularly through the laminated construction which allow sound waves to pass therethrough with a fluid impervious film sealing the openings and enabling the wall covering to be used as a fluid impervious covering yet with the film allowing substantially unobstructed passage of the sound waves therethrough.

Abstract: This invention relates to acoustic liners having a plurality of cavities defining Helmholtz resonators in which the adjacent cavities are asymmetrical causing a pressure imbalance across the coupling means (tube, slot or aperture) between these cavities in the frequency range of interest. Such liners are particularly useful in turbofan engine noise reduction applications where low frequencies are encountered.

Abstract: A composite board structure comprising a corrugated fiberboard consisting of at least one liner and at least one corrugated paper medium bonded to the liner by means of a layer of a hot melt adhesive material, the liner being covered with a facing web of a woven or unwoven fabric which has its fibers scatteringly filling in perforations formed in the liner and sticking to the layer of the hot melt adhesive material so as to be securely fastened to the liner without use of any adhesive material between the liner and the facing web.

Abstract: A perlite sound absorbing plate and a sound insulating wall constructed by arranging a number of said plates side by side and by assembling together into one integral body are disclosed. The plate is composed of a mixture including 1,000 cm.sup.3 by bulk volume of formed perlite particles each having a diameter of 0.1 to 7.0 mm, 100 to 140 g of cement, liquid rubber latex containing 5 to 20 g of solid ingredients and a suitable amount of water and produced by press molding with a compression ratio of 1.10 to 1.30. The wall is constructed by assembling a number of said plates each provided with a side groove with the aid of supporting columns and reinforcing plates, each having a ridge adapted to be engaged with the side groove of said plate.

Abstract: A sound insulation chamber delimits a gaseous flow channel and including onant cavities housed within a double wall. The cavity vents are ducts which open into the channel flush with the inner wall and project into the interior of the cavities.

Abstract: Core noise, a low frequency noise component believed to be partly caused by the combustion processes within the engine, and turbine noise, a higher frequency noise component caused by the interaction of high velocity gases with the engine's turbine, are attenuated by noise absorbing structures that are disposed within the engine's nozzle and that in part define the physical geometry of the nozzle duct. The nozzle is formed of an outer sleeve and an inner generally bulb-shaped plug which are coaxially arranged to define an annular nozzle duct that channels the flow of gases rearwardly from the outlet of the engine's turbine. The plug has a hollow interior that is partitioned into a plurality of cavities that communicate with the nozzle duct via perforations provided in an outer wall of the plug.

Abstract: A shield for an assembly includes a member of generally corrugated construction, which is uniquely configured to substantially prevent the passage of liquid contaminants impinging thereon. The invention is especially concerned with the provision of an acoustical assembly employing such a shield.

Abstract: A sound absorbing body which can effectively be utilized as an exterior sound absorbing wall or an interior wall of a house is disclosed. The sound absorbing body comprises a number of sound absorbing cavities inclined at an angle .alpha. which is smaller than 80.degree. with respect to a transverse horizontal sectional plane of the body, the sound absorbing cavities being opened at the sound incident surface.

Abstract: Sound-suppressing structure comprising stacked acoustic panels wherein the inner high frequency panel is mounted for thermal expansion with respect to the outer low frequency panel. Slip joints eliminate the potential for thermal stresses, and a thermal expansion gap between the panels provides for additional relative thermal growth while reducing heat convection into the low frequency panel.

Abstract: This invention is a new and unique acoustical board formed of fire retardant materials which board has the unique qualities of being fire retardant, sound absorbing, heat insulating, and decorative, and may be formed virtually in any desired size and shape. It is composed of fiberglass reinforced melamine resin panels or the like having one grooved surface covered by fiberglass cloth with perforations suitable to admit sound waves into the grooved areas of the underlying board in such manner as to trap, and debilitate such sound waves therein, and, it has been particularly formed so as to be oil impervious, while retaining the sound deadening qualities by the insertion of a thin membrane of oil impervious material between the fiberglass cloth and the melamine panel.