Abstract: A sound absorbing structure is constituted of a vibration plate and a rear air layer and is installed in a luggage compartment or trunk which is separated from a cabin in a vehicle. Sound waves entering into the luggage compartment drive the vibration plate to vibrate so that acoustic energy is converted into mechanical energy and is consumed by way of vibration of the vibration plate. By appropriately setting parameters and dimensions, the sound absorbing structure efficiently absorbs low-frequency sound such as road noise occurring due to friction of wheels of the vehicle traveling on a road.

Abstract: This invention is a device that is mounted on the top of a movable office partition to improve the acoustical efficacy of the partition. It is equally effective on new or on existing partitions and can be made to fit all the major brands in the movable partition market. It is attractive, lightweight, durable, inexpensive to manufacture and easy to install. The device is able to absorb incident sound and redirect diffracted sound to a path that will reduce sound levels reaching a listener in adjacent cubicles.

Abstract: A sound absorption block installed at a music box, a gymnasium, a studio, etc. to prevent sounds from being heard outside, and a method of constructing the same are disclosed. The present invention provides a sound absorption block, including a lower plate where a plurality of unit structures are regularly arranged in horizontal and vertical directions, the unit structure having rectangular an opening that becomes gradually smaller; and an upper plate arranged on the lower plate to divide each of the openings of the unit structures in four parts. Accordingly, the sound absorption block of the present invention may be made of metals, as well as inexpensive building residues, etc. because a sound wave was decreased and offset regardless of the materials.

Abstract: An acoustic assembly including a thin sound absorbing panel supported by foldable mounting brackets is adapted to be mounted upon the walls of an indoor listening enclosure. The space behind the panel functions as an acoustic diffusion chamber which augments the acoustic performance of the panel. A number of such assemblies are employed in a manner such that the panels are offset from the wall and downwardly angled.

Abstract: An acoustical dampening barrier, for an opening in a wall, that is translatable to an open position to allow access to the opening, the fixed barrier including a first barrier layer made of at least one of a rigid and semi-rigid material, a second barrier layer fixed to the first barrier layer on a side of the first barrier layer where a sound to dampen is emitted made of an acoustic material with sound attenuation characteristics, a third barrier layer fixed to the second barrier layer on a side of the second barrier layer where a sound to dampen is emitted made of an acoustic material with sound absorptive characteristics, and a seal material connected to at least one of the opening in the wall, the first barrier layer and the third barrier layer to further dampen a sound emitted when the fixed barrier is translated to a closed position to prevent access to the opening.

Abstract: A sound insulation/absorption structure, a sound insulation/absorption device, and a structure having these applied thereto and a member constituting the same, are capable of insulating or absorbing sound by stiffness control. The sound insulation/absorption structure comprises a film member, such as a polymer film or metal foil, and a frame body having at least one annular opening, the film member being fixed to the frame body, the section of the film member surrounded by the frame body being of a curved shape such as a dome, wherein the resonance frequency of the in-plane stretching of this curved shape is set at a frequency equal to or higher than the audible frequency band, so as to insulate or absorb sound by the elastic force of the film. The film member may be replaced by an acrylic, polyethylene terephthalate or other plastic plate, an aluminum or other metal plate, or a veneer or other plate member, molded into a curved shape, such as a dome, a semi-cylinder and a cone.

Abstract: An acoustic scatterer element (10) incorporates a plurality of convex surfaces (38.1, 38.2) have a plurality of associated curvatures in a corresponding plurality of different directions. A plurality of acoustic scatterer elements of various sizes in a cooperative relationship with one another provide for diffusing acoustic waves in a room (14).

Abstract: A thermally expandable material is provided that, once expanded, has a Young's storage modulus E? between 0.1 MPa and 1000 MPa, a loss factor of at least 0.3 (preferably, at least 1) and preferably a shear storage modulus G? between 0.1 MPa and 500 MPa at a temperature between ?10 and +40 degrees C. in the frequency range 0 to 500 Hz. Such materials are useful in combination with a carrier to form a dissipative vibratory wave barrier that effectively reduces the transfer of vibrations from a vibration generator, as may be present in a vehicle.

Abstract: A set of acoustic components having complementarily tessellated shapes such that they may be nested together to constitute a rectangular parellelepiped, suitable for efficient storage and shipping. Each component also has a flat side. The shape set is further defined such that many aesthetically attractive, sculpture-like configurations may be created through installation of the components on a flat surface of a building such as a wall or ceiling, while substantially modifying the acoustic properties of the building feature. Acoustically absorptive, reflective, and diffusive components can be used in combinations with each other in order to achieve desired acoustic treatment of the building feature. Several methods of fabrication of the acoustic components are disclosed.

Abstract: To obtain a wide passenger compartment space, the thickness of a heat insulating acoustical layer is reduced, and for this purpose, a comfortable in-car environment is obtained by using a vacuum insulating panel which combines high heat insulating performance and sound insulating performance. A heat insulating acoustical layer 20 is formed on one surface of a lightweight alloy structure 10 of double skin construction by using a vacuum insulating panel 21 as a middle member and sandwiching two surfaces of the panel with elastic sound absorbing materials 22, 23 made of a nonwoven fabric or a foamed body, and the heat insulating acoustical layer is covered with an interior material 24. Owing to this construction, the transmission loss of a noise which transmits from the double skin structure side is improved by the mutual actions of the elasticity of the sound absorbing material and the rigidity of the vacuum heat insulating panel.

Abstract: A wall-mountable acoustic device for absorption of sound in an indoor area is constructed of self-supporting interbonded rockwool mat material. The primary component made of the mat material is shaped in semi-cylindrical configuration. End panels of rockwool mat of similar composition are attached to the opposite ends of the semi-cylindrical configuration to enclose the configuration except for an open rear extremity of rectangular perimeter. When attached to a flat wall, a totally enclosed semi-cylindrical chamber is defined. In a preferred embodiment, further improvement of sound absorption properties is achieved by way of a diaphragm disposed within the semi-cylindrical configuration.

Abstract: A system for improved sound absorption, including a substrate of porous insulation material and of a first air flow resistance, and a facing material attached to the substrate and of a second air flow resistance, wherein a total system resistance is a combination of the first and second air flow resistances, and wherein the total system resistance and the second air flow resistance are of relatively low values.

Abstract: The invention concerns a sound-proofing panel, in particular a rotorcraft structural or lining panel: the sound-proofing panel (1) comprises at least two opposite plates (2, 3, 5, 6) forming between them a closed internal space (4), and an aggregate (7) including at least solid elements (8) in contact and which fills entirely said internal space (4).

Abstract: An apparatus for manipulating the air temperature within an interior compartment of a vehicle includes a compressor, a condenser, and an evaporator interconnected in a manner to remove heat from air in the interior compartment. A thermostatic expansion valve is connected between the condenser and evaporator, and includes an inlet and an outlet. A silencer screen is positioned at the outlet of the thermostatic expansion valve to reduce turbulence in refrigerant flow exiting the thermostatic expansion valve.

Abstract: Acoustical attenuating devices (52) and method of forming them. The attenuating devices (52) include an exterior layer (64), a sound absorption layer (66), and multiple perforated layers (68) coupled to the sound absorption layer (66). The perforated layers (68) include a perforated structural layer (70) and a perforated substrate layer (72). The perforated structural layer (70) and the perforated substrate layer (72) provide structural stiffness and define multiple resonating tubes (88) that attenuate sound.

Abstract: Embodiments of aperiodic tiling of a single asymmetrical diffusive base shape employ welled or stepped one-dimensional or two-dimensional diffusors, a single or compound curved surface, or an aperiodic geometrical form. Surfaces are tiled in any orientation offering an unlimited number of tiling patterns. In the preferred embodiments of the present invention, a smooth transition between adjacent “tiles” is achieved. Using a single tileable asymmetric base shape reduces the number of shapes requiring manufacture while allowing modulation. The present invention even contemplates extending the inventive techniques into three-dimensional shapes to form volume diffusors. The technique employed to design diffusors to be used in accordance with the teachings of the present invention may rely upon visual appearance, a random sequence, a number theory sequence, or use of an optimization program.

Abstract: Microperforated polymeric films and sound absorbers using such films are provided. The microperforated polymeric films may be relatively thin and flexible and may further include holes having a narrowest diameter less than the film thickness and a widest diameter greater than the narrowest diameter. The microperforated polymeric films of a sound absorber may also have relatively large free span portions, which, in certain embodiments, may vibrate in response to incident sound waves.

Abstract: The present invention provides for an acoustically absorbent porous panel that is both rigid and resistant to sagging caused by moisture. The acoustically absorbent porous panel is comprised of at least two layers. The first layer is a facing layer formed from a cured aqueous foamed cementitious material. The foamed cementitious material comprises on a wet basis about 53% to about 68% by weight cement, about 17% to about 48% by weight water, about 0.05% to about 5% by weight fiber, and about 0.01% to about 10% by weight surfactant. Additionally, pores distributed within the cured material comprising about 75% to about 95% by volume of the material. The second layer is a backing layer that is affixed to the facing layer.

Abstract: Aerogel particles, in particular in the form of composite materials, are used to deaden structure-borne and/or impact sounds.

Abstract: The invention provides a method for acoustic closure of an installation of a row of sound isolation modules within a host building encompassing the modules. One or more acoustic absorbing closure panels are mounted to form a partition in front of the row of modules, thus forming two acoustically separate regions. The absorbing panels are comprised of one or more sound absorbing materials between a front and rear surface. The front surface faces the region exterior to the installation within the host building. The rear surface faces the installation.

Abstract: The invention concerns a sound-proofing panel, in particular a rotorcraft structural or lining panel: the sound-proofing panel (1) comprises at least two opposite plates (2, 3, 5, 6) forming between them a closed internal space (4), and an aggregate (7) including at least solid elements (8) in contact and which fills entirely said internal space (4).

Abstract: An acoustic isolator is placeable between a sound producing body and arresting surface. The acoustic isolator includes a foam member having a first surface for receiving the sound producing body and a second surface for engaging the resting surface. The foam member is composed of a supportive foam member capable of substantially preventing the transfer of sound induced vibrations between the sound producing body and the resting surface while sustaining an internal deflection of less than about thirty percent.

Abstract: A surface wave apparatus is disclosed having reduced sound attenuation across a surface along a known path having a path distance when compared to sound attenuation along a same path distance through air. The surface wave apparatus includes a plurality of cells defining a first surface. Sound presented at the first surface forms a surface wave over the surface and proximate thereto. Each cell includes four bounding walls and a bottom. Two of the bounding walls act to guide the sound within the known path and two are disposed across the known path to form a structure supporting formation of surface waves.

Abstract: A noise attenuation device having an array of quarter wave resonators which have varying mouth widths disposed adjacent an aperture or ventilation opening having a predefined width. The resonators are tuned to a resonant frequency, increasing from one face of the attenuation device to another, and so that the mouth widths are each greater than the width of the aperture or ventilation opening, respectively. Optionally, a second array tuned to a different frequency may be disposed on the opposite side of the aperture and the aperture may be kinked so that there is no direct line of sight through the device.

Abstract: A flexible sound shielding curtain contains a plurality of sound insulating sheet inserts encased within pockets or otherwise secured on the exterior surfaces of the panels of a curtain. The sound insulating sheet inserts may be constructed of a combination of materials selected and configured such that sound impinging upon the curtain is absorbed or alternatively reflected. The sound shielding curtain can be tuned to insulate an area from a select range of frequencies inherent in select environments. Tuning may be accomplished through the selection and installation of sound insulating sheet inserts configured to reflect or absorb audible acoustical energy. The sound insulating sheet inserts are readily removable to permit periodic laundering of the curtain fabric and to provide adaptability for a number of applications. Sound shielding curtain(s) can be selected, configured, installed, and extended in such a manner as to provide sound reduction in a localized space.

Abstract: Disclosed is a multi-layered, substantially rigid and self-supporting acoustical panel. Preferably, the panel includes an acoustically absorbent semi-rigid core having a substantially continuous interior porosity. The panel also includes an acoustically permeable face layer applied to a first face of the core, wherein the face layer is adapted to allow acoustical energy to pass through the face layer and into the acoustically absorbent core. The panel also includes a flame-retardant, calendered paper backing adapted to be applied to the core. According to the present invention, the panel may also include a flame-retardant adhesive adapted to attach the calendered, flame-retardant paper backing to the core.

Abstract: A motorized and computer controlled TRIFFUSOR® acoustical treatment system includes a plurality of TRIFFUSOR® banks mounted in various locations within a listening room. Mechanical actuators such as gears and sprockets are employed to mechanically couple the individual units of each bank together. In the preferred embodiment, an electrical motor is coupled into the gearing so that rotation of the electrical motor results in indexing of the different faces of each TRIFFUSOR® unit to the three possible positions (absorptive, reflective or diffusive) facing the interior of the listening room. A programmable logic-controlled motor control unit is provided and programmed to coordinate activation of different TRIFFUSOR® banks throughout the listening space.

Abstract: A sound reducing system comprises a housing, acoustic baffle, and acoustic netting. The acoustic baffle is covered with a waterproof protective casing which protects the acoustic baffle from dirt and moisture without interfering with its acoustic properties, and allows it to be cleaned with fluids. The housing comprises an inner pan and an outer pan which are pivotally coupled. The acoustic baffle and the acoustic netting are disposed within the housing, but can be removed for cleaning when the housing is opened. When the acoustic baffle and acoustic netting members are placed back within the housing, they are protected from damage.

Abstract: The modular anechoic panel system provides modular anechoic panel for construction of anechoic chambers particularly advantageous for use in sound testing and measurement. The modular anechoic panel incorporates into a single structural member the elements of structural support, transmission loss features, and the wedge base and air space elements of an anechoic wedge thus providing enhanced protection to elements of the anechoic wedge. The modular anechoic panel provides a durable structural member and, as assembled, form a structural shell of an anechoic chamber having a reduced footprint. Additionally, the modular anechoic panel provides a compression clip mounting system for conveniently mounting and replacing wedge tips, thus allowing for use of standard wedge tip materials and easy assembly, repair and replacement of damaged wedge tips.

Abstract: A sound absorbing light fixture (42) installed in a surface system, such as an elevator ceiling system (40), of an enclosed interior, such as the interior (32) of an elevator cab (32) is presented. The light fixture (42) comprises a frame (46) disposed in fixed relationship to the surface system, the frame (46) having an interior rear surface and interior side surfaces extending outwardly from the rear surface to define a cavity (50). A light source (48) is supported by the frame (46) within the cavity (50). Additionally, a light diffuser (44) is disposed in fixed relationship to a front portion of the frame (46) between the light source (48) and the enclosed interior. The installed light fixture (42) enhances a sound absorption coefficient, e.g., above 0.6, of the surface system for a predetermined frequency range of sound energy, e.g., 300-600 Hz.

Abstract: A projection screen and a projection screen system for an acoustic room. A projection screen includes a flexible screen material mounted within a system of retainers. The screen material is tautly retained within the a system of retainer members, and may be treated so that its airflow resistance is variable. Acoustical material is disposed on the wall behind the screen. Acoustical paneling is chosen according to the acoustical characteristics of the room, so that acoustical modal pressure peaks and nulls forming primarily along the length of the room can be reduced. The projection screen can be surrounded by further acoustical material, so that the entire wall can be used to tune the room. The acoustical material surrounding the projection screen is mounted within a second retainer system in which covering fabric is retained.

Abstract: Microperforated polymeric films and sound absorbers using such films are provided. The microperforated polymeric films may be relatively thin and flexible and may further include holes having a narrowest diameter less than the film thickness and a widest diameter greater than the narrowest diameter. The microperforated polymeric films of a sound absorber may also have relatively large free span portions, which, in certain embodiments, may vibrate in response to incident sound waves.

Abstract: An acoustic panel is constructed of a rectangular frame (1). A first face of the panel is covered by a membrane (2) which is at least substantially transparent to audio frequency sound waves. The interior of the frame (1) behind the membrane (2) includes sound absorbent material (5). The second face of the panel is covered by a closure member (4) which is opaque to audio frequency sound waves.

Abstract: A rigid lightweight surfacing panel for providing a new surface for existing panels in acoustical panel ceiling systems, the surfacing panel having a degree of flex so to allow it to be pushed into place in a support system in underlying matched relation with an existing panel whereby a new decorative surface to impart a change in the existing decor or to decoratively replace damaged, worn or soiled surfaces can be provided without need for removing the existing panel. In a preferred embodiment porous surfacing panels are each made by combining a pair of flexible strand mats under heat and pressure with an interposed lightweight fibrous web of heat meltable binder and providing the combination with a decorative exposed surface layer which allows transmission of sound through the combination to an overlying existing ceiling panel.

Abstract: The broadband surface-like absorber of the invention is used, in particular, for absorbing troublesome airborne noise in the acoustic frequency range. The broadband surface-like absorber, which operates on the Helmholtz resonator principle, is distinguished by a checkerwork of irregular construction, the webs of which are aligned with their narrow sides perpendicular to the principal surface of the perforated plate and the side edges of which are connected in a sound-pressure-resistant and fluidtight manner on the sound side to the rear side of the perforated plate and, on the rear side, to an extended-area cavity boundary aligned with the same orientation as the perforated plate to form differently tuned chamber resonators.

Abstract: Fabric retainers and methods for installing the fabric retainers within an acoustically treated room. The fabric retainers have a fabric retaining portion, and a chase or a raceway for running wires within the interior of the retainers. The chase has an open side which allows fasteners to be installed through the base of the retainer, and which allows for the insertion of wires into the chase. Retainers also have a retainer groove in which an acoustical fabric is secured, and a fabric retaining pocket to store the inserted fabric. Alternative retainer embodiments have two retainer grooves. A removeable cover is provided to secure the wiring within the chase, and to conceal the wiring within the chase. Also disclosed are methods for combining various retainer embodiments within a structure.

Abstract: A panel which diffuses sound incident thereupon is provided having a rectangular perimeter and wedge-shaped configuration wherein the front surface of the panel is angularly disposed with respect to its flat rear surface. The front surface contains a series of parallel elongated depressions. A multitude of such panels are employed along with sound reflecting and sound absorbing panels to produce a wall-mounted assemblage of sound-interactive panels capable of desirably modifying the subjectively perceived quality of sound in a room or auditorium.

Abstract: This invention provides a muffling panel of a new-type lightweight construction having a function of effectively excluding sounds in low and medium sound ranges and high muffling and sound-absorbing properties in a relatively low frequency band area, and also having at least two parallel diaphragms, a frame body for fixing of the diaphragms and a vibration transmitting mechanism which links to the diaphragms and can mechanically transmit reverse phase vibration, wherein the vibration transmitting mechanism converts vibration of one of the diaphragms which vibrates when receiving a sound into reverse phase vibration thereof to transmit it to the other of the diaphragms, thus causing the other of the diaphragms to displace inward or outward and vibrate simultaneously with one of the diaphragms according to vibration energy of the above original sound.

Abstract: An acoustic testing device is relatively small enough and light enough to be transported from business to business and room to room, and yet still has acoustic characteristics sufficient to characterize a test item's noise profile in a relatively short period of time. The device preferably achieves this result by providing inner and outer housings coupled through noise and vibration isolation, the inner housing having at least some mutually non-orthogonal walls, and the sound detection apparatus comprising spatially translating microphones.

Abstract: An appropriate binary sequence is used to create an acoustical treatment surface having desired parts with reflective properties and desired parts having absorptive properties resulting in the net effect of partially diffusive, partially absorptive properties. A genetic algorithm is designed to search for optimal 1D and 2D configurations for the acoustical treatments. A genetic algorithm essentially mimics the process of evolution that occurs in biology and is a known mathematical technique. During the course of genetic optimization, the fitness of individual sequences for the desired purposes is calculated. A useful fitness function includes terms that optimize the desired percentage of reflectivity and absorptivity. Through use of genetically optimized binary sequences, a curved surface may be constructed and optimized to find the best shape to achieve even scattering. The curved surface produces a dramatic improvement in effectiveness of diffusion.

Abstract: The modular anechoic panel system provides modular anechoic panels for construction of anechoic chambers particularly advantageous for use in sound testing and measurement. The modular anechoic panel incorporates into a single structural member the elements of structural support, transmission loss features, and the wedge base and air space elements of an anechoic wedge thus providing enhanced protection to elements of the anechoic wedge. The modular anechoic panels provides a durable structural member and, as assembled, form a structural shell of an anechoic chamber having a reduced footprint. Additionally, the modular anechoic panel provides a compression clip mounting system for conveniently mounting and replacing wedge tips, thus allowing for use of standard wedge tip materials and easy assembly, repair and replacement of damaged wedge tips.

Abstract: A low reverberating room for the entire auditory range. In particular, for ow frequency ranges below 100 Hz, in which the walls and ceiling are covered with sound absorbers. The sound absorbers on a surface of about 70-90% of a room, not including the floor, have a depth of <0.5 m preferably <0.3. The sound absorber also has a closed, plane but acoustically permeable surface, are built up of multiple layers. The sound absorbers are about 20-70% in similarity to composite-plate resonators. They are also provided with inside plates, made of metal or heavy foil, which are designed of varying thickness for absorption in various frequency ranges.

Abstract: To provide a sound absorbing structure having a superior sound absorbing characteristic and an external appearance of the sound absorbing structure which does not cause flicker or the like, by disposal, for example, in the front of an air chamber, a plurality of ribs (2a) are disposed on one surface of the sound absorbing board body (2), and a plurality of through-holes (3) are provided in basal portions (2b) between the ribs (2a) to form a porous structure. Concealing materials (5) are provided between the ribs (2a) of the sound absorbing board body to conceal the through-holes (3), respectively.

Abstract: A sound attenuating element is provided which comprises a closed cell foam layer (2) having a plurality of channels (4) formed therein. The element is, in use, placed adjacent a surface such that an air gap is formed between the foam layer and the surface. The channels couple to the air gap to form a plurality of Helmholtz resonators.

Abstract: Apparatus for supporting an acoustical diffuser panel within a structure. A preferred apparatus includes a rigid support member fabricated from an acoustically absorptive material. The support member has a bottom and upstanding side walls that define a well that is sized to receive a diffuser panel therein. The diffuser panel may comprise a plurality of column members that are integrally formed with a planar bottom surface and extend therefrom. At least one column member is longer than at least one other column member. Another diffuser panel that can be successfully used has a series of elongated columns that extend for the width or length of the panel. At least one column member extends a distance above the bottom of the support member that differs from the distance that another column extends above the support member when the panel is received therein. A method for installing at least one acoustical diffuser assembly into a wall structure and an acoustical wall structure are also disclosed.

Abstract: A multilayered insulating panel having improved acoustic insulating properties and mechanical strength has two outer facings and a soft synthetic foam core having cavities. The foam core with the cavities is in intimate contact with the facings. The cavities are arranged so that the gaps between the core material and the outer facings are in alternate patterns with respect to the opposing outer facings.

Abstract: A sound absorber is made primarily out of a triangular fiberglass panel. The front face of the sound absorber is covered with porous material. The side edges of the panel rest against walls in a room. A fiberglass pad may be attached to the back face of the panel.

Abstract: The invention concerns a plate resonator for absorbing sound and including a thin front plate with high elasticity and low internal friction, e.g., made of metal; a back plate which likewise has high elasticity but which has high internal friction; an all-over solid connection between the front and back plates in the form of a bonded connection (e.g. double-sided adhesive tape); and a border which is closed all around by the back plate but does not prevent sound entering the back plate from the side.

Abstract: An acoustic diffuser panel for diffusing sound of a range of frequencies comprises a sound reflective surface having a plurality of generally parabolic shaped wells interconnected by arcuate junctions. The shaped wells are bounded by an outer lip. The sound reflective surface of the panel is generally curvilinear. The number of wells of the panel is equal to a modulus. The modulus is the lowest prime number exceeding the quotient of the highest frequency of the range of frequencies divided by the lowest frequency of the range of frequencies. The wells at their opening each have particular width less than or equal to the quotient of the speed of sound divided by the product of two times the lowest frequency of the range of frequencies. Each well has a depth equal to a value of a quadratic residue number theory sequence, n.sup.

Abstract: A sound absorber comprises a bottom portion and a structure portion joined to the bottom portion and closed off from outside, the structure portion having chamber walls forming hollow chambers, the hollow chambers being formed like small boxes or cups. Between the bottom portion and the structure portion, in the region of the hollow chambers, welds are formed between parts of the chamber walls of the structure portion and the bottom portion such that the chamber walls are in part welded to the bottom portion. In part the chamber walls project towards the bottom portion without being welded thereto such that an air gap is formed between an end of these chamber walls and the bottom portion, the hollow chambers forming a common air space enclosed between the structure portion and the bottom portion.