Abstract: A duct includes a duct body defining an inlet, an outlet, and a channel connecting the inlet and the outlet. The duct body also defines an upstream resonator. The upstream resonator includes an upstream annular cavity external to the channel and an annular perforated plate coplanar with the upstream annular cavity. The duct body further defines a downstream resonator. The downstream resonator includes a downstream annular cavity external to the channel and an annular neck coplanar with the downstream annular cavity.

Abstract: An acoustic panel comprising a cellular structure, such as a honeycomb structure, having cells that open at least onto a first frontal face of the structure. The panel comprises a capsular skin which is fastened to the first frontal face of the cellular structure next to a plurality of cells. The capsular skin including a continuous layer of material, in one piece, forming capsules that extend into the cellular structure. At least one channel is provided at the apex of each capsule for the passage of acoustic waves. Such a panel effectively attenuates the noise of aircraft engines, in particular, the low frequencies. It is extremely easy to manufacture industrially, the capsular skin being able to be obtained by molding with polymerization in situ, the polymerizable material then adhering to the cellular structure while it polymerizes.

Abstract: The invention discloses a system for reducing ambient noise generated from an acoustic domain, comprising a landing pad comprising a plurality of zones of varied porosity levels over specified sections, and a plurality of perforated channels across the plurality of zones of varied porosity levels, the perforated channels comprising a plurality of aqueous sheets placed at an inlet of the perforated channels and along the perforated channels. Also disclosed is a method of reducing ambient acoustic noise produced by unmanned aerial vehicle (UAV) operations, the method comprising the steps of absorbing acoustic energy produced by the UAV via a plurality of zones of varied porosity levels, present in a UAV landing pad, resulting in reducing sound-pressure transmission-loss of propeller downwash across the plurality of zones of varied porosity.

Abstract: A method for manufacturing a soundproofing assembly involving providing a first panel of honeycomb structure, fastening an intermediate plate against a second face of the first panel, adhesive-coating a layer of adhesive on the intermediate plate, providing a second panel of honeycomb structure, bonding the first face of the second panel to the layer of adhesive, and perforating the intermediate plate and the layer of adhesive through the cells of the first panel or the cells of the second panel at the bonding zone of the second panel. Such a method makes it possible to save time by dispensing with additional preparation steps.

Abstract: Sound absorbers using distributed absorption units each having an extended neck are provided. The absorption units can be, for example, Helmholtz resonators with extended neck (HRENs). The absorption units can be distributed in a lateral fashion, for example, in a checkerboard fashion with laterally, non-diagonally adjacent units having a different extended neck length and/or diameter. Each absorption unit can be, for example, a cylinder-structure core sandwiched between a back wall and a perforated plate.

Abstract: A space-saving broadband resonator configured to install within and utilize inner space of other components and includes a resonator insert having a tubular pipe elongated along a central axis, the tubular pipe having a circumferential outer wall having a plurality of perforation holes spaced apart and extending radially through the circumferential outer wall. An interior of the tubular pipe forms a gas flow duct. A plurality of annular disk-shaped walls provided on and projecting radially outwardly from the tubular pipe. Adjacent annular disk-shaped walls spaced axially part from each other define resonator chambers therebetween. A bell mouth is formed at the second axial end of the tubular pipe, the bell mouth flared radially outwardly.

Abstract: a sound control device for pneumatically driven mechanical devices and method of use of said device, the device configured to create a sealed intermediary gas medium between the atmosphere and surfaces of the pneumatically driven mechanical device where vibrational energy is generated and where exhaust flow travels, the sound control device further configured to carry such energy and exhaust away from the source where it may be released into the atmosphere in a quieter manner.

Abstract: Noise attenuating devices and methods, precursors and abrasive blasting masks for manufacturing noise attenuating devices are disclosed. An exemplary method disclosed herein includes bonding a facing sheet of the noise attenuating device to a cellular core and then perforating the facing sheet. Perforating the facing sheet may be performed by abrasive blasting using a mask configured to prevent the abrasive blasting of an underlying structure.

Abstract: A dynamic acoustic ceiling baffle and a dynamic acoustic ceiling baffle system, that includes multiple shaped baffles that can be quickly and easily installed onto construction ceiling hangers without the need for additional tools, to provide an aesthetically pleasing image, such as an undulating image, along with a reduction in unwanted noise or room acoustics.

Abstract: A stator of an electric machine is already known, comprising stator teeth and grooves formed between the stator teeth, in which electrical conductor elements of an electrical individual coil winding are provided as individual coils, wherein an interconnection is provided on at least one end side of the stator, which has a ring section and multiple, in particular a number corresponding to the number of stator teeth, tooth sections protruding from the ring section in the radial direction. The interconnection ring comprises multiple bus bars for interconnecting the electrical individual coils of the electrical winding. The individual coils are produced from a conventional conductor material, e.g. copper. In the stator according to the invention, an electrical winding made of CNT conductor elements is provided.

Abstract: A turbocharger air intake silencer with adjustable cavity space structures is provided. The turbocharger air intake silencer comprises a silencer connecting flange and a first resonator device. The first resonator device comprises a first silencer sealing plate, a first annular sound absorption cavity body, a first rotary table, a first rotary steering gear and a first valve. A first sound absorption cavity is enclosed by the first silencer sealing plate, the first annular sound absorption cavity body, the first valve and the first rotary table. A first sound absorption cavity inlet pipe is arranged beside the first sound absorption cavity. The first sound absorption cavity and the first sound absorption cavity inlet pipe form a Helmholtz resonator. The first rotary steering gear is mounted on the silencer connecting flange. The rotary steering gear is connected with a first rotary rack.

Abstract: A soft boundary structure is implemented using a resonator structure capable of receiving sound or vibration, establishing resonance coupled with received sound or vibration, and creating a reflection with a pi phase factor. A soft boundary is located on or closely adjacent the resonator structure. The soft boundary cooperates with the resonator structure to attenuate the sound or vibration.

Abstract: A terminal unit for a heating, ventilation, and air conditioning (HVAC) system includes a housing defining a plenum and having a first panel and a second panel disposed opposite each other. The first panel has a first outlet opening and a second outlet opening, and the second panel has a first inlet opening configured to receive a first air flow and a second inlet opening configured to receive a second air flow. The terminal unit includes a sound attenuator including an inlet configured to receive the first air flow and an outlet configured to discharge the first air flow into the housing via the first inlet opening. The terminal unit further includes first and second blowers. The first blower is configured to discharge air from the plenum via the first outlet opening, and the second blower is configured to discharge air from the plenum via the second outlet opening.

Abstract: A constant velocity muffler assembly for maximizing the exhaust performance of an internal combustion engine includes a muffler that is fluidly coupled to an exhaust pipe of an internal combustion engine to facilitate exhaust gasses to pass through the muffler. A cylinder is disposed within the muffler and the muffler swells outwardly at a middle of the muffler to accommodate the cylinder. The cylinder is oriented to extend along a flow axis of the muffler with respect to the exhaust gasses. In this way the cylinder is configured to deflect sound waves from the internal combustion engine thereby reducing a noise level of the internal combustion engine.

Abstract: The application relates to a wheel with a sound absorption device, wherein the sound absorption device is arranged in a wheel air chamber to reduce acoustic resonance, the sound absorption device comprises two resonance sound absorption structure units which are connected in parallel, a first sound absorption frequency band of a first resonance sound absorption structure unit and a second sound absorption frequency band of a second resonance sound absorption structure unit are adjacent to each other or partially overlap with each other, and the resonance frequency of the wheel air chamber is contained at the adjacent part of the first sound absorption frequency band and the second sound absorption frequency band or in the overlapping area of the first sound absorption frequency band and the second sound absorption frequency band.

Abstract: The present disclosure relates generally to acoustic panels, for example, suitable for use in a ceiling to control sound. The present disclosure relates more particularly to an acoustic ceiling panel including an acoustic substrate formed of a porous material having an air flow resistivity of at least 300 kPa*s/m2. The acoustic substrate includes an upper face and a lower face with a pattern of perforations formed therein, where the pattern of perforations covers at least 6% of the area of the lower face. The acoustic ceiling panel also includes a backing layer disposed over the upper face of the acoustic substrate and a veil disposed over the lower face.

Abstract: A motor includes: a stator having teeth protruding radially inward from the inner peripheral surface of a stator core; coils wound on the teeth; a shaft rotating on the inside radially of the stator core; a rotor core affixed to the shaft and radially centered on the rotation axis of the shaft; permanent magnets arranged on the outer peripheral surface of the rotor core; projecting poles which are formed projecting radially outward between the permanent magnets adjacent to each other in the circumferential direction of the outer peripheral surface of the rotor core, and with which the projecting contact surfaces of the permanent magnets are in contact. The stator is formed by stacking electromagnetic steel sheets in the direction of the rotation axis of the shaft. At least one of the axial ends of each of the permanent magnets projects further than an axial end of the rotor core.

Abstract: A pickup diaphragm includes a pickup part, a suspension edge and an outer edge, wherein the pickup part includes a non-planar surface. The suspension edge includes a deformable surface, with a joint surface being respectively configured on the inner and outer sides of the deformable surface, and the joint surface on the inner side being fixedly connected to the periphery of the non-planar surface. In addition, the outer edge includes a ring groove, in which one side of the ring groove is set as a connection end while the other side thereof is set as an opening end, the inner side of the connection end is fixedly connected to the joint surface located on the outer side, and a stethoscope head can be inserted through the opening end such that the ring groove is placed in sleeve on the outside of the stethoscope head.

Abstract: A sound insulation plate includes a patterned frame and an elastic membrane, wherein the patterned frame includes a central pattern region and multiple peripheral pattern regions arranged around the central pattern region, the multiple peripheral pattern regions being separated from the central pattern region by a separation bar, and wherein the elastic membrane is mounted on the patterned frame to block passage of air and converts airborne sound waves into elastic waves.

Abstract: A tele-health apparatus includes a telephone having a microphone, an auscultation piece to acquire sounds, and a solid medium acoustically coupling the auscultation piece to the microphone. The auscultation piece is part of a stethoscope, and the solid medium is a windpipe of the stethoscope. The tele-health apparatus also includes an otoscope operable to be disposed in front of a camera of the telephone. A clip holds the stethoscope and the otoscope, and is fixed to the phone. Software modules installed in the telephone enable the tele-health apparatus to engage a user in a two-way audio and/or video consultation with a physician at a remote device in real-time.