80 results about "Acoustical resistance" patented technology

Acoustic parameters of an ear are recorded by measuring the impedance of the ear canal. A first pressure microphone measures the sonic pressure. A second pressure microphone measures the sonic pressure through a calibrated acoustic resistance. The sound energy flux is determined by the difference between the measured sonic pressures. The impedance is calculated from these results.

A system for dissipating sound shock waves within a vehicle tire includes a wheel upon which a tire is mounted to create an internal air chamber defined by the wheel and the tire. A flow-resistant barrier is coupled to the wheel or the tire and defines an air cavity within the internal air chamber. The barrier comprises a material that provides an acoustical resistance to sound shock waves passing therethrough. The air cavity defined by the barrier has a volume such that air within the cavity offers relatively small impedance to the passage of shock waves through the barrier and into the air cavity. The barrier also can produce frictional heat when displaced by a shock wave, thereby converting energy of the shock wave to heat to reduce noise associated therewith.

A system for dissipating sound shock waves within a vehicle tire includes a wheel upon which a tire is mounted to create an internal air chamber defined by the wheel and the tire. A flow-resistant barrier is coupled to the wheel or the tire and defines an air cavity within the internal air chamber. A porous spacer can support the barrier with respect to the tire and also can provide a flexible energy damper. The barrier comprises a material that provides an acoustical resistance to sound shock waves passing therethrough. The air cavity defined by the barrier has a volume such that air within the cavity offers relatively small impedance to the passage of shock waves through the barrier and into the air cavity. The barrier also can produce frictional heat when displaced by a shock wave, thereby converting energy of the shock wave to heat to reduce noise associated therevvith.

The invention relates to the technical field of acoustic resistance material testing, in particular to an acoustic resistance material testing device which comprises a plurality of acoustic resistancetubes, a sliding pair, a feeding device, an acoustic absorption cotton adjusting sliding rod and a fine adjusting bolt. The acoustic resistance tubes comprise a head end acoustic resistance tube anda tail end acoustic resistance tube; the sliding pair comprises a sliding block and a sliding rail, and the sliding rail is installed on a supporting device through an installation plate and bolts. The feeding device is mounted on the sliding rail; the tail end acoustic resistance tube is installed on the supporting device and located on one side of the sliding rail. The sound absorption cotton adjusting sliding rod is installed in the tail end acoustic resistance tube and provided with a scaleplate. The fine adjusting bolt is connected into the counter bore of the sliding block in a screwed mode and located on the side close to the sound absorption cotton adjusting sliding rod, and the fine adjusting bolt and the sound absorption cotton adjusting sliding rod are coaxial. Linear feeding isachieved through the feeding device, motion can be directly transmitted, no transfer device is needed, reverse motion is avoided, testing steps are simplified and the accuracy of testing results is improved.

The invention discloses a manufacture method of a microporous or micro-slit array body and a product. The method comprises the following steps of: making a plastic rough blank or material; molding and processing by using a die; solidifying a formed array body substrate and microspores or micro slits; and obtaining the microporous or micro-slit array body. The cross section of a die core of the die in use is gradually reduced from the root to the top, the processed microporous or micro-slit cross section is correspondingly and gradually reduced, and an acoustic resistance layer is reserved between the microporous or micro-slit bottom and the substrate bottom. The manufactured microporous or micro-slit array body has the thickness larger than 5mm, and the material in use is transparent or light-transmitting. The product comprises illuminators which are arranged in the microspores or micro slits or behind the array body, distributed and connected according to patterns, characters or a matrix and driven by a preset program. The invention can once form and process microporous or micro-slit slabs of a plurality of inorganic or organic materials and can realize low material cost and low processing cost.

A method that improves the energy distribution from a multi-way loudspeaker into free space. The method reduces MF energy through the use of small depressurizing slit openings down the inner half of the HF stems. The openings are sized to be large enough to present a leak path for the secondary energy to migrate out of the stem with no return path.

The present invention proposes a loudspeaker installation structure with high stability, which includes a loudspeaker unit. The front end of the loudspeaker unit is provided with a fixed cover, and the fixed part of the fixed cover is fitted on the front plate of the speaker box and covers the outside of the window hole. , the fixed part is locked and fixed by three first bolts, and the end of the first bolt is welded to fix a first fixed block, the first fixed block is provided with a first slot, and one end of the plug-in column is inserted In the first slot of the first fixed block, the other end of the plug-in column passes through the buffer plate and the acoustic resistance material is inserted into the first backing plate in sequence, the first backing plate is arranged between the acoustic resistance material and the partition wall, and the second backing plate is arranged between the acoustic resistance material and the partition wall. The two fasteners pass through the second backing plate, the partition wall and the insertion column located in the first backing plate are locked and fixed through thread cooperation; the invention has good shock absorption effect, good stability and increased service life.

The invention discloses a single-hole ultrasonic detection device and method for continuous integrity and rock penetration depth of a concrete diaphragm wall, the detection device comprises an equipment host, an ultrasonic transducer and an ultrasonic signal feedback device, the equipment host comprises an ultrasonic transmitting module and an ultrasonic signal acquisition module, the ultrasonic transmitting module is used for generating ultrasonic waves and transmitting the ultrasonic waves out through the ultrasonic transducer, and the ultrasonic transducer is used for collecting and recycling the reflected ultrasonic waves, converting the recycled ultrasonic wave information into electric signals and transmitting the electric signals back into the equipment host. And the signal feedback device analyzes and calculates acoustic resistance parameters of the target medium by judging the reflected ultrasonic waves, so that medium information encountered in the ultrasonic wave propagation process is judged. The device is different from traditional ultrasonic detection equipment, ultrasonic sound pressure value acquisition is adopted, and the judgment of medium information and the calculation of the rock entering depth of the diaphragm wall are realized through the acoustic impedance information relationship between the ultrasonic sound pressure value and the target medium.

An acoustic filter including a valve system with acoustic valves arranged in a sound passage for controlling the acoustic resistance of respective apertures based on a control signal for selecting an attenuation of a sound pressure level of transmitted sound compared to that of received sound. The acoustic filter is adapted to provide the selection of the attenuation from a sequence of predetermined attenuations based on a selection of the control signal. Each attenuation in the sequence corresponds to acoustic valves providing the apertures with a respective predetermined acoustic resistance, wherein the acoustic resistances of subsequent attenuations in the sequence are adapted to correspond with a linear increase or decrease in the attenuation of the sound in decibels.

The present invention relates to a microphone module comprising a first directional microphone comprising a front sound inlet and a front membrane, a second directional microphone comprising a rear sound inlet and a rear membrane, and a middle sound inlet arrangement being acoustically connected to the front and rear membranes, said middle sound inlet arrangement comprising acoustical resistance means arranged at least partly therein. The microphone module aims at generating a cardioid and an anti-cardioid response, or alternatively any other back-to-back polar patterns.

An acoustic wave device includes an energy confinement layer, a piezoelectric layer made of Y-cut X-propagation lithium tantalate having a cut angle in a range from about −10° to about 65°, and an IDT electrode. Electrode fingers of the IDT electrode include an Al metal layer and a high acoustic impedance metal layer having a Young's modulus equal to or more than about 200 GPa and an acoustic impedance higher than Al. The high acoustic impedance metal layer is closer to the piezoelectric layer than the Al metal layer. A wavelength specific film thickness t_LT of the piezoelectric layer is expressed by t_LT≤1λ. The total of normalized film thicknesses obtained by normalizing the film thickness of each layer of the electrode finger by a density and Young's modulus of the Al metal layer satisfies T≤0.1125t_LT+0.0574.

The invention discloses an acoustic device and an electronic apparatus,. The invention comprises a sound production unit and a first housing, the sound production unit is installed on the first housing to form a sound production assembly, a first closed cavity is formed between a vibrating diaphragm of the sound production unit and the first housing, and the first housing is provided with a flexible deformation part; the acoustic device comprises a second shell, a second closed cavity is formed between the second shell and the first shell, and the flexible deformation part is located between the first closed cavity and the second closed cavity; acoustic resistance materials used for slowing down the flow speed of airflow are arranged in the first closed cavity and located between the soundproduction unit and the flexible deformation part. According to the acoustic device, the resonant frequency can be effectively reduced, the low-frequency-band sensitivity of the product is greatly improved on the whole, and the listening effect can be improved.