A backing member includes: a resin body including a lower surface and an upper surface opposite to each other; a plurality of leads each of which extends in a first direction from the lower surface toward the upper surface, and that are embedded at pitches in the resin body; and a plurality of insulating spacers each of which is provided between adjacent ones of the leads and extends in a second direction intersecting with the first direction, and that contact the leads.

A method of using an acoustic resonator including receiving at a first stage of a resonator an incoming acoustic wave. The method further includes resonating the incoming wave with a flexible membrane, a taper of the flexible membrane, and a cavity of a first stage, thereby producing synergistic effect on a resulting acoustic resonance. Additionally, the method includes transforming an acoustic energy associated with the incoming acoustic wave into an elastic energy, wherein the elastic energy is channeled through the flexible membrane, thereby reducing an intensity of the incoming acoustic wave and resulting in a first reduced incoming acoustic wave. Further the method includes transferring the first reduced incoming acoustic wave through a hole of a neck of the flexible membrane. The method also includes transferring a first pressure wave caused by a perturbation in the flexible membrane into a second stage, thereby producing a second acoustic wave.

Method and System for avoiding howling disturbance especially on conferences, wherein the method comprising the steps of using a howling detector unit implemented inside a multipoint control unit to receive an audio stream input from a client, analyzing the audio input with the howling detector in order to verify if howling noise is present, using at least two of a skewness analysis, a flatness analysis, a crest analysis, a rolloff analysis and preventing the audio stream input to be forwarded as an output to an audio mixer, if howling noise is present.

Method and System for avoiding howling disturbance especially on conferences, wherein the method comprising the steps of using a howling detector unit implemented inside a multipoint control unit to receive an audio stream input from a client, analyzing the audio input with the howling detector in order to verify if howling noise is present, using at least two of a skewness analysis, a flatness analysis, a crest analysis, a rolloff analysis and preventing the audio stream input to be forwarded as an output to an audio mixer, if howling noise is present.

A combustor component of a combustor for combusting fuel to produce a combustion gas includes a combustion cylinder forming a passage for the combustion gas, a first acoustic device which internally includes a first cavity communicating with the passage via a first through hole formed in the combustion cylinder, a second acoustic device which is located on a radially outer side of the first acoustic device so as to cover the first acoustic device, and internally includes a second cavity communicating with the passage via a second through hole formed in the combustion cylinder, and a first communication passage causing the first cavity and an outer space of the combustion cylinder to communicate with each other without via the first through hole and the second cavity.

A noise damper for a compressed-air system, for a brake system of a utility vehicle, including: a housing having an inlet channel for a compressed-air stream and with a chamber for accommodating sound-damping material, in which the inlet channel and the chamber are separated, perpendicularly with respect to the compressed-air stream, by a separating plate which is closed in a central region and which, in an outer peripheral region of the compressed-air stream, has multiple openings for introducing the compressed air directly into the chamber. Also described are a related pneumatic brake system and method.

The present invention relates to a hose arrangement (100) for creating a bubble curtain (BS) in bodies of water, comprising at least one air hose (4) including an interior space (4b) enclosed by a wall (4a), where a perforation (9) consisting of individual punctures (9a) is introduced in the wall (4a) at least in an upper, first circumferential area (B1), from which air can be discharged, when the interior space (4b) is pressurized, for creating a bubble curtain (BC) extending in the longitudinal direction (X) of the air hose (4), and a ballast receptacle (20) including a receiving area (8) extending in the longitudinal direction (X), in which an elongates ballast element (21) is received.

The invention provides that the air hose (4) is jacketed by a support sheath (10) including material bars (10a) and intermediate openings (10b), the air hose (4) being connected in a connecting area (15) via the support sheath (10) to the ballast receptacle (20), and the openings (10b) being positioned at least in the first circumferential area (B1) of the air hose (4) so as to allow air to be discharged from the perforation (9) in the air hose (4).

A bell and hammer rotational device is shown and described. The bell and hammer rotational device includes a frame which is made up of at least two side walls. The frame has a spindle rotatably secured thereto. A rotational device is coupled to the spindle such that the spindle will rotate the rotational device, when the spindle is rotated. At least one bell is secured about a perimeter of the rotational device. A bell hammer is secured to the frame. The bell hammer is positioned such that it will strike the at least one bell, at least once, with each revolution of the rotational device.

A bell and hammer rotational device is shown and described. The bell and hammer rotational device includes a frame which is made up of at least two side walls. The frame has a spindle rotatably secured thereto. A rotational device is coupled to the spindle such that the spindle will rotate the rotational device, when the spindle is rotated. At least one bell is secured about a perimeter of the rotational device. A bell hammer is secured to the frame. The bell hammer is positioned such that it will strike the at least one bell, at least once, with each revolution of the rotational device.

An acoustic attenuation structure for a gas turbine engine includes a periodic structure having a first unit cell, the first unit cell having a first central body and a first axial tube disposed on the first central body and a second axial tube disposed on the first central body, opposite the first axial tube, each of the first axial tube and the second axial tube being in fluid communication with one another through the first central body.