Abstract: In an acoustic resonator, an actuator allows a piston to reciprocate axially at very small amplitude at high speed. Owing to pressure fluctuation in the acoustic resonator involved by reciprocal motion of the piston, fluid is sucked into and discharged from the acoustic resonator via a valve device at the top end of the acoustic resonator. The acoustic resonator is covered with a gas guide with a space. The valve device is cooled by a fan at the top end of the gas guide.

Abstract: An improvement is provided in loudspeaker enclosures characterised by a frequency response having at least one null due to a cavity mode. The improvement comprises introducing an aperture at a high pressure region of said enclosure for provided a pressure leak thereby substantially eliminating said at least one null.

Abstract: The invention relates to an acoustically effective wheel house covering for vehicles, i.e. a wheel house covering which can reduce transmission of splash water noises in the passenger compartment of the vehicle and which can absorb the sound of rolling tires on a roadway, which wheel house covering comprises several layers of material.

Abstract: The invention relates to a soundproof thermal shield (3), particularly for motor vehicles, comprising an aluminum support (4), a noise-absorbing layer (6) and an aluminum thermal covering (7). In order to make the inventive soundproof thermal shield easy to recycle while obtaining a great thermal shielding effect and noise-absorbing power, a permeable mat made of knitted aluminum is used as a noise-absorbing layer (6), said knitted aluminum being superimposed in several layers and pressed so as to form the permeable mat. The inventive thermal shield is thus made of a single material. Preferably, the support (4) is made of a microperforated aluminum sheet while the thermal covering (7) is preferably made from an aluminum film.

Abstract: A loudspeaker includes a diaphragm, an edge, and a voice coil. The diaphragm includes a groove having a concave cross section. Also, the diaphragm is in a horizontally or vertically elongated shape. The edge is coupled to an outer circumference of the diaphragm, and has a roughly half-round shaped cross section. The voice coil is bonded to the groove. The voice coil is thicker than a depth of the groove. Also, the voice coil has a cross section in which a dimension in a direction along a plane of the diaphragm is longer than a dimension in a direction perpendicular to the plane of the diaphragm.

Abstract: A medical stethoscope head (1) comprises a body (2) with an inlet pipe and at least one diaphragm portion (4) provided with a diaphragm (5) at its lower surface. At least one identifying-personalizing ring (11) provided with identifying-personalizing means (14) is mounted in any area of an upper surface (10) of said diaphragm portion (4), opposite to said diaphragm (5). The identifying-personalizing ring (11), at its surface adjacent to the diaphragm portion (4), is provided with at least one locating element for explicit locating the identifying-personalizing ring (11) in defined angular position in relation to an axis (3?) of said inlet pipe (3) of said body (2).

Abstract: Methods and apparatus for generating a signal with a signal generator comprising a tool body disposed in a tubular member. A first and second electromagnets are disposed within the tool body such that the second electromagnet is opposite the first electromagnet. A power supply selectively provides electrical current to the first and second electromagnets so as to displace the tubular member and generate a signal in the surrounding formation.

Abstract: The present invention relates to a muffler for a line conveying gas and airborne sound, in particular for an exhaust system of an internal combustion engine, preferably in a motor vehicle. The muffler has a housing in which there are at least two inside pipes for carrying gas in the interior of the housing and which contains at least one inside plate for reinforcing the housing. The two inside pipes are inserted one inside the other in a sliding seat area and are axially movable in relation to one another.

Abstract: An exhaust device includes an exhaust pipe connected at its upstream end to a cylinder head of the engine and an exhaust muffler connected to the downstream end of the exhaust pipe for suppressing the generation of noise from a heat insulating cover that covers a part of the exhaust pipe. A heat insulating cover covers a portion of the exhaust pipe near the engine and a stay is fixed to the heat insulating cover. The stay includes a supporting plate portion curved so as to partially surround the outer circumference of the exhaust pipe. A first vibration isolating member is provided that is sandwiched between the outer circumference of the exhaust pipe and the supporting plate portion, a band member is tightened to mount the supporting plate portion to the exhaust pipe, and a second vibration isolating member is sandwiched between the supporting plate portion and the band member.

Abstract: A compact noise silencer for a blower, including an L-shaped back wall having a sound adsorbent media and side walls defining a triangular enclosure, an inlet opposite one portion of the back wall and a central outlet opposite the back wall having a filter directing air into a blower. In the disclosed application, the blower directs air into a burner which heats the air for various applications.

Abstract: A noise absorbing structure of an instrument panel of a vehicle includes a first noise absorbing panel, provided in the instrument panel disposed in front of a driver seat of the vehicle, a second noise absorbing panel, provided in the instrument panel disposed in front of a front passenger seat of the vehicle, and a third noise absorbing panel, provided in the instrument panel that is disposed in front of a moisture removing ventilation port.

Abstract: A coupling device is interposed between an electronic or electro-acoustic component and a supporting structure for draining, transmitting and dissipating vibratory energy generated within the component, while isolating the component from vibratory energy emanating from the support structure, utilizing a ball rolling along a bearing surface in directions away from and toward an equilibrium position, with the ball biased toward the equilibrium position by magnetic attraction forces.

Abstract: A downhole receiver for gathering seismic and sonic data from inside a borehole includes a substantially tubular housing adapted for axial connection to a tool string, and one or more sensors. A damping element is provided to flexibly couple each sensor to the tubular housing. An actuator extends the one or more sensors substantially radially with respect to the tubular housing to clamp the sensors against the wall of the borehole. In selected embodiments, the sensors may be one or multiple component geophones, accelerometers, hydrophones, vibrometers, or the like.

Abstract: A blocking device for mounting within a space defined within a hollow structure includes a holder and an expandable member. The holder is adapted to be mounted within the space. The expandable member is supported on the holder and is expandable by heat to form a foam member in order to block or substantially close the space. The holder includes a holder plate extending substantially perpendicular to the longitudinal axis of the space and supporting at least one side of the expandable member. The expandable member includes a constriction absorbing portion that is deformed so as to absorb potential constriction of the expandable member at the beginning of the expansion process of the expandable member.

Abstract: In an exhaust system, exhaust manifolds are connected to two banks provided in a V-type engine of a vehicle, respectively, to which front pipes each having a catalytic converter are connected to the exhaust manifolds, respectively. A muffler is provided at an exhaust downstream side of the exhaust pipes, and a rear pipe is further connected to the exhaust downstream side of the muffler. The front pipe has its rear end portion located near a through hole formed in the rear pipe. A path length of one of the front pipes from the bank to the muffler is made shorter than that of the other front pipe.

Abstract: A portable terminal apparatus with a telephone function such as a portable telephone, for efficiently emitting a voice from a speaker from both a front face and a backside of a housing. The portable terminal has: a first cover that includes a first sound outlet for emitting a sound from the speaker through the front of the portable terminal apparatus; a second cover that includes a second sound outlet for emitting a sound from the speaker through the back of the portable terminal apparatus; and a gasket accommodated at a position sandwiched between the first cover and the speaker.

Abstract: A soundproofing material for vehicle having a laminated structure comprising two sound absorbing layers and an interlayer interposed therebetween, characterized in that the interlayer is formed by bonding and laminating on the respective side of an air-impermeable film made of a thermoplastic resin film having a thickness of from 7? to 50? heat-fusible films having a thickness of from 7? to 50? made of a thermoplastic resin film having a lower melting point than that of the air-impermeable film using a multi-layer inflation method and the soundproofing material is heat pressure-molded so that the heat-fusible film is melted to cause the sound absorbing layers to be bonded to the respective side of the air-impermeable film.

Abstract: An auxiliary mounting device 10 for an in ceiling speaker system comprises a ceiling reinforcing element 11 and an elongate element 21. The ceiling reinforcing element 11 includes a flat plate portion 12 and a vertical portion 14 provided to extend vertically from the flat plate portion, 12. The vertical portion 14 is capable of being in a slidable state in which the vertical portion 14 is vertically slidable and in a fixed state in which the vertical portion 14 is fixed so as not to vertically displace.

Abstract: An acoustic module for a hearing aid device has at least one microphone and at least one earphone (acoustic output transducer) combined together as a unit, the unit including a signal-processing unit for feedback suppression that is connected with the microphone and the earphone. Feedback signal portions are removed from the microphone signal by the signal-processing unit. The acoustic module places acousto-mechanical components within a unitary component, with acousto-mechanical characteristics that can be measured and included in the signal processing for feedback suppression.

Abstract: There is disclosed a sound attenuation panel comprising, a rigid frame divided into a plurality of individual cells, a sheet of a flexible material, and a plurality of weights. Each weight is fixed to the sheet of flexible material such that each cell is provided with a respective weight and the frequency of the sound attenuated can be controlled by suitable selecting the mass of the weight.