Abstract: Provided is a soundproof structure that is small and light and can reduce a noise with a high specific frequency of a sound source at a plurality of frequencies at the same time.

Abstract: Described herein is an acoustic building panel comprising: a body comprising a fibrous material and having a first major surface opposite a second major surface and a side surface extending there-between, the fibrous material comprising polyester fiber in an amount of at least 70 wt. % based on the total weight of the fibrous material; wherein the body has a bulk density as measured between the first major surface, the second major surface, and the side surface, the bulk density ranging from about 4.8 lb./ft3 to about 6.0 lb./ft3.

Abstract: An acoustic metamaterial (AMM) passive impedance matching technique to enhance the acoustic performance of porous/poro-elastic sound absorbing materials is disclosed. An AMM passive matching device is implemented by achieving negative refractive index with double negative parameters, i.e., negative effective mass density and effective bulk modulus scheme, using various acoustic elements. The AMM technique consists of meta material architecture of acoustic inductive open tubes positioned strategically around the outside surfaces of the porous media and perforated screens inserted inside porous media to generate complex acoustic impedance load of the porous media; the inductance defined by a predetermined lengths of the open tubes. The device includes open tubes extending from the porous media to the outside ambient medium generating the desired reactive load over the broadband frequency region of the complex acoustic impedance of the porous media.

Abstract: Outflow valve assemblies for an aircraft, aircraft including an outflow valve assembly, and methods for installing an outflow valve assembly on an aircraft, are provided. In one example, an outflow valve assembly includes a louver that is movably disposed to at least partially cover an opening formed through a fuselage on an aircraft. A motor is coupled to the louver and is configured to move the louver between a closed position to obstruct fluid communication through the opening and an open position to allow fluid communication through the opening between inside and outside of the aircraft. A sound absorptive panel is disposed adjacent to the opening to attenuate noise that is generated when the louver is in the open position.

Abstract: An acoustic panel including a first face sheet having a plurality of openings; a core attached to the face sheet, the core comprising a plurality of cells each having cell walls; and a plurality of noise attenuating features each comprising at least one of the openings in combination with one of the cells, wherein the openings are disposed away from the cell walls so that the noise attenuating features suppress the transmission of acoustic waves in acoustic communication with the openings.

Abstract: A soundproofing structure comprises a jacket having an external surface and an opposite internal surface defining an inner compartment. A resilient and deformable soundproofing material is contained within the Inner compartment and engages the internal surface. Constricting elements are mounted to the jacket for constriction of the jacket to provide inner surface pressure against the soundproofing material for compression thereof. The constricting elements are releasable for selectively releasing inner surface pressure against the soundproofing material for expansion thereof against the inner surface. The soundproofing structure defines a size that is selectively modifiable by selective releasing of the contacting elements.

Abstract: Provided is a soundproof structure that is small and light and can reduce noise with a high natural frequency of a sound source at a plurality of frequencies at the same time. The soundproof structure according to the embodiment of the present invention includes a plurality of membrane-like members that are overlapped to be spaced from each other, a support that is made of a rigid body and supports each of the plurality of membrane-like members so as to perform membrane vibration, an inter-membrane space that is sandwiched between two adjacent membrane-like members among the plurality of membrane-like members, and a rear surface space that is formed between one membrane-like member at one end of the support in the support among the plurality of membrane-like members and the one end of the support, in which each of the plurality of membrane-like members absorbs a sound by performing the membrane vibration in a state where the one end of the support is closed.

Abstract: A glass wool panel, intended to be used as an acoustic panel, has a density of less than or equal to 130 kg/m3, an air flow resistivity of between 30 and 120 kPa·s/m2, a Young's modulus of between 0.5 and 4 MPa.

Abstract: A rotary apparatus includes a motor, a plurality of gears, and a sensor configured to detect a rotation angle of one of the plurality of gears. The sensor includes a first connection terminal electrically connecting to the outside, and a base portion. The first connection terminal is disposed at the base portion. A second connection terminal is disposed at the base portion.

Abstract: Systems for building modular quarter-wavelength resonators, and arrays of said resonators, include interlocking blocks having channels in them. Different block varieties can include those having straight channels and those having curved channels, to facilitate assembly of resonators of any desired configuration. Resonator length, and therefore resonance frequency, can be easily designed by adjusting the number of blocks used for a particular resonator.

Abstract: An acoustic system is provided for the perfect absorption of bending waves. The acoustic system includes a longitudinally extending substrate (plate or beam) defining upper and lower opposing major surfaces. At least two mechanical resonators are coupled to the upper major surface and separated by a distance dimension that may be based on a fraction of a magnitude of the wavelength of a selected bending wave. Each mechanical resonator includes a rigid mass component and a connecting element. The mechanical resonators are configured to block or absorb bending waves that propagate through the substrate. The connecting elements maintain the rigid mass component an elevated distance from the upper major surface of the beam when in a rest position. The connecting element can be a spring and damper; a flexible rubber/plastic component with an axial stiffness; or a base connecting component with a flexible arm, optionally with vibration damping.

Abstract: An electronic device having a housing structure that is configured to receive at least one glass cover is disclosed. The glass cover serves to cover a display assembly provided within the electronic device. The glass cover can be secured to the housing structure so as to facilitate providing a narrow border between an active display area and an outer edge of the housing structure. The enclosure for the electronic device can be thin yet be sufficiently strong to be suitable for use in electronic devices, such as portable electronic devices.

Abstract: A soundproof structure body includes a first tube structure and a second tube structure connected to the first tube structure and having a cross-sectional area different from the first tube structure, in which a structure body having a cross-sectional area smaller than a cross-sectional area of the first tube structure is installed in the first tube structure, and a transmission loss in a case where the structure body is installed in the first tube structure with respect to a case where the structure body is not installed in the first tube structure is positive at two frequencies adjacent to each other and difficult to generate an air column resonance mode in the first tube structure. This soundproof structure body generates a soundproof effect even at frequencies other than air column resonance of a tube structure such as a duct or a muffler, has a small size, and can obtain a high transmission loss in a wide-band.

Abstract: A ventilation assembly and methods of forming the same includes a ventilation grille having reducing acoustic bodies configured to attenuate sound of the ventilation assembly. Arrangement of the acoustic bodies can form phononic crystal to attenuate sound and can be tuned to desired sound bands to reduce sounds.

Abstract: A method for manufacturing a sound absorption structure comprising a cellular panel, a porous layer positioned on a cellular panel first face, a reflective layer positioned on a cellular panel second face and a plurality of acoustic elements positioned in the cellular panel. The method comprises the steps of producing, for each acoustic element, a recess in the cellular panel opening out onto the first and second faces of the cellular panel, inserting the acoustic elements into their recesses, laying an anchoring layer on the second cellular panel face, curing or polymerization at a first pressure to connect each acoustic element to the cellular panel and/or to the anchoring layer, putting in place the porous layer and the reflective layer, and curing or polymerization at a second pressure to connect the porous layer and the reflective layer to the cellular panel.

Abstract: Flexible electronic devices may be provided. A flexible electronic device may include a flexible display, a flexible housing and one or more flexible internal components configured to allow the flexible electronic device to be deformed. Flexible displays may include flexible display layers, flexible touch-sensitive layers, and flexible display cover layers. The flexible housing may be a multi-stable flexible housing having one or more stable positions. The flexible housing may include a configurable support structure that, when engaged, provides a rigid support structure for the flexible housing. The flexible internal components may include flexible batteries, flexible printed circuits or other flexible components. A flexible battery may include flexible and rigid portions or may include a lubricious separator layer that provides flexibility for the flexible battery.

Abstract: A two-stage water-lift and water separation muffler for use with marine electrical generators installed onboard marine vessels. A first stage water-lift muffler has internal tunable sound suppression structure to provide a first stage of exhaust silencing, and a second stage water separator having internal tunable sound suppression structure to provide a second stage of exhaust silencing while separating entrained cooling water from exhaust gases. The combined first stage water-lift muffler and second stage water separator include internal baffling and silencing structure which is easily adaptable to different generator configurations thereby allowing for structural adjustments to the muffler to optimize sound suppression and minimize backpressure for particular generator and/or exhaust conditions.

Abstract: A sound absorption device and a method of manufacturing the same are provided. The sound absorption device includes a sound absorbing panel including first elements, second elements, third elements, and fourth elements arranged in different directions, wherein a cross-section of at least one of the first through fourth elements has a distorted circular shape, a distorted polygonal shape, or a distorted elliptical shape.

Abstract: An acoustic core includes an array of resonant cells. The array may include a plurality of coupled resonant cells respectively defining an antecedent resonant space and a subsequent resonant space, with at least one cell wall having one or more wall-apertures defining a pathway between the antecedent resonant space and the subsequent resonant space. The array may include a plurality of high-frequency resonant cells respectively defining a high-frequency resonant space and being matched with respective ones of the plurality of coupled resonant cells. A cross-sectional dimension of the one or more wall-apertures defining the pathway between the antecedent resonant space and the subsequent resonant space may be less than a cross-sectional dimension of the antecedent resonant space and/or a cross-sectional dimension of the subsequent resonant space.

Abstract: Compact sound attenuation systems for fluid ducts are provided having one or more sound attenuation units that can be absorptive or reflective, depending on design. Each sound attenuation unit has one or more encircling Helmholtz resonators that fully encircle the duct in a lateral direction. Sound attenuation units can be coincident with the duct well and either interior or exterior to the duct, or in some instances can be partly interior and partly exterior to the duct. Sound attenuation systems can be tuned for maximum attenuation of a single resonance frequency, or can include multiple units of different frequencies for broadband attenuation.