148 results about "Noise attenuation" patented technology

Various illustrative systems, devices, and methods for face masks are provided. In general, a face mask is configured to provide cooling therapy to a user wearing the face mask. In an exemplary implementation, the face mask includes a thermoelectric cooling device, such as a Peltier device, a thermoelectric cooler (TEC), or other thermoelectric cooling device. The face mask includes a fan configured to blow air configured to dissipate the heat created by the thermoelectric cooling device. The face mask includes a noise attenuation system configured to attenuate the generated noise that is radiated into the environment, and thus, heard by the user due to use of the fan.

The invention relates to the technical field of aircrafts, and discloses a noise-considered urban low-altitude unmanned aerial vehicle path optimization method, which comprises the steps of urban environment rasterization and environment parameter setting; constructing an unmanned aerial vehicle noise attenuation model; calculating a noise interference critical distance and building sensitivity weight assignment; solving a noise interference grid matrix; a low-altitude unmanned aerial vehicle path planning model; and improving A * algorithm design. According to the method, the urban environment is rasterized, environmental parameters are set, an outdoor noise attenuation model is established by integrating geometric divergence, atmospheric absorption, ground effect and other factors, the propagation law of unmanned aerial vehicle noise in a complex environment is accurately described, the overall noise exposure and the sensitive area noise exposure are remarkably reduced while the flight safety is guaranteed, and the unmanned aerial vehicle noise attenuation performance is improved. The calculation efficiency is improved through the critical distance, path redundancy is avoided, collaborative optimization of noise control and operation efficiency is achieved, and technical support is provided for standardized operation of urban ultra-low-altitude unmanned aerial vehicles.

In this power supply device, a main circuit includes a core, a first common mode coil, a second common mode coil, a first connection line, and a second connection line, and a noise attenuation unit includes an auxiliary coil having a third winding and a third coating, a capacitor connected to the first connection line, and a resonance suppression unit that includes an amplification unit and a low-pass filter connected to an output terminal of the amplification unit and that is provided between the auxiliary coil and the capacitor.

In one aspect, the invention provides an audio encoding method characterized by a decision being made as to whether the device which will decode the resulting bit stream should apply post filtering including attenuation of interharmonic noise. Hence, the decision whether to use the post filter, which is encoded in the bit stream, is taken separately from the decision as to the most suitable coding mode. In another aspect, there is provided an audio decoding method with a decoding step followed by a post-filtering step, including interharmonic noise attenuation, and being characterized in a step of disabling the post filter in accordance with post filtering information encoded in the bit stream signal. Such a method is well suited for mixed-origin audio signals by virtue of its capability to deactivate the post filter in dependence of the post filtering information only, hence independently of factors such as the current coding mode.

The invention belongs to the technical field of noise source impedance extraction, and discloses a noise source impedance extraction optimization method and system considering the sensitivity of an insertion loss method, and the method comprises the steps: extracting an equivalent circuit of noise source impedance based on the insertion loss method, and calculating a noise attenuation coefficient through the equivalent circuit, a noise source impedance amplitude and phase information are sought according to the noise attenuation coefficient; calculating relative sensitivity by using the noise source impedance amplitude and phase information, and analyzing an influence rule of a noise attenuation coefficient on noise source impedance extraction precision based on the relative sensitivity; and generating a setting rule of a noise attenuation coefficient according to the influence rule, extracting a frequency band meeting the noise source impedance requirement by using the setting rule, and determining the inductance to perform noise source impedance extraction optimization operation. According to the method, firstly, analytical expressions of noise source impedance amplitude and phase are deduced, the influence rule of the noise source impedance property on noise source impedance extraction precision is analyzed, and the requirement required to be met by noise source impedance extraction precision is improved.

The invention relates to the technical field of audio processing, and discloses a voice recognition method and system based on a neural network, and the method comprises the steps: firstly obtaining a real-time audio stream of a target scene, extracting a time-frequency feature group, analyzing a pulse coding sequence, and constructing a voice network architecture; identifying an acoustic feature cluster by using the acoustic feature cluster, matching a preset framework hierarchical topological relation, and optimizing node weight to generate an adaptive mapping network; based on this, analyzing a sound source propagation path, identifying a multipath effect factor, calculating a frequency domain coupling coefficient, and performing hierarchical fusion to obtain a mixed feature tensor; querying a tensor adaptive response trajectory, extracting a phase distortion feature and a signal-to-noise ratio index, and calculating a signal-to-noise attenuation entropy; and finally, determining a robust recognition level, reconstructing a sound source acquisition dimension and formulating a sound recognition scheme. According to the invention, the voice recognition precision in a complex environment can be improved.

The invention discloses a high-resolution processing method and device for converted waves, electronic equipment and a medium. The method comprises the steps that initial converted waves of seismic signals are obtained through radial component direction rotation operation on the seismic signals; carrying out noise reduction processing and consistent amplitude compensation processing on the initial converted wave to obtain an adjusted converted wave; arranging the adjusted converted waves in a crossed manner, and dividing the arranged adjusted converted waves into a plurality of pieces of wide-azimuth loss offset OVT domain data; according to the method, multiple pieces of OVT domain data are subjected to noise attenuation through a filtering method, the multiple pieces of OVT domain data are processed according to a deconvolution processing method so as to improve the resolution ratio of the OVT domain data, initial converted waves are obtained, noise reduction processing and consistent amplitude compensation processing are carried out on the initial converted waves and partitioned initial converted waves, and the resolution ratio of the OVT domain data is improved. Therefore, the signal-to-noise ratio of the converted wave is improved, and the processing requirement of the high-resolution converted wave is met.

The invention relates to the technical field of path planning, in particular to a multi-unmanned aerial vehicle low-noise path planning method and system, and the method comprises the steps: carrying out the modeling of a flight environment of an unmanned aerial vehicle; establishing a sound source directivity model of the unmanned aerial vehicle, and evaluating the noise influence of the flight of the unmanned aerial vehicle on the noise sensitive area according to a noise attenuation formula; and performing path planning by using an acoustically-driven artificial potential field algorithm, generating a flight path of the unmanned aerial vehicle by calculating an attraction potential field, a repulsion potential field and an interaction force among the unmanned aerial vehicles, and updating path planning in real time. According to the method, the noise characteristics are converted into a repulsive force mechanism, the noise characteristics are combined with the artificial potential field, the noise evaluation process is simplified, rapid and real-time path planning is achieved, the noise sensitive area can be dynamically avoided in real time during path planning, and the influence on the noise sensitive area is greatly reduced.

The utility model belongs to the technical field of reactors, and particularly relates to an extra-high voltage shunt reactor oil tank composite noise reduction structure which comprises a rubber plate fixedly installed in an oil tank wall, the outer side of the rubber plate is attached to the surface of the inner side wall of the oil tank wall, and a sound absorption hole-free paperboard is fixedly installed on the inner side of the rubber plate. A double-layer composite perforated plate sound absorption mechanism is fixedly installed on the inner side of the sound absorption hole-free paperboard, gaps are reserved among the rubber plate, the sound absorption hole-free paperboard and the double-layer composite perforated plate sound absorption mechanism, and a gap is reserved between two layers of perforated plates of the double-layer composite perforated plate sound absorption mechanism. The double-layer composite perforated plate sound absorption mechanism comprises a first perforated paperboard and a second perforated paperboard. The composite noise attenuation structure composed of the rubber plate and the multiple layers of insulating paper plates is arranged on the inner side wall of the oil tank, vibration waves transmitted from insulating oil are blocked and weakened through material combination of different media, vibration noise can be reduced, and the composite noise attenuation oil tank is an important measure for solving the problem of noise of an electric reactor.

The invention discloses an intelligent design system and method for an aviation airborne porous system complex flow channel shell part, and relates to the technical field of intelligent design, and the system comprises a data obtaining module which is used for obtaining a three-dimensional flow channel shell model, a working condition parameter set and a manufacturing limit; the feature extraction and arrangement band generation module is used for generating a candidate arrangement band; the hole group design and optimization module is used for generating a circumferential shallow cavity communication scheme and hole group arrangement; the acoustic impedance synthesis module is used for constructing equivalent surface complex impedance; the performance index calculation and association module is used for constructing system insertion loss and system additional voltage drop indexes; the multi-target tradeoff and solution verification module is used for obtaining a definite solution; and the design and manufacturing output module is used for taking the determined solution as parameterized computer aided design data and formulating manufacturing key points. According to the method, the arrangement area can be accurately selected in the complex flow channel, the controlled hole group can be constructed, and both noise attenuation and flow loss are considered.

A method that includes determining a level of sound within an acoustic environment captured by a microphone; receiving, from a headset worn by a user, data indicating an audio processing mode in which the headset is operating; determining a level of attenuation of the sound based on the audio processing mode and the level of sound; estimating sound exposure based on at least the level of attenuation and the level of sound; and transmitting the sound exposure to an application program.

The invention discloses a vibration and noise reduction transmission system and rotary excavating power equipment, and relates to the technical field of power transmission, the vibration and noise reduction transmission system comprises a driving device, a driven device and a transmission device, the transmission device is in contact connection with the driving device and the driven device, and the transmission device comprises a pressurizing part and a vibration reduction part; the pressurizing part is a hard part and is used for power transmission, the vibration reduction part is an elastic energy absorption part and is used for generating elastic deformation when the pressurizing part transmits power, and the vibration transmission frequencies of different positions of the vibration reduction part are different. Buffering of collision is achieved through elastic deformation, noise attenuation is achieved from the interior of a sound source, the noise reduction efficiency is improved, vibration energy is transmitted through an elastic structure, fatigue damage to parts is avoided, the force transmission performance and the noise reduction requirement can be considered, the vibration transmission frequencies of different positions of the vibration reduction part are different, the fixed frequency is eliminated and stabilized, and mechanical waves are isolated.

The invention relates to the technical field of noise calculation, and provides a method and device for determining the sound pressure level of noise after multi-path diffraction attenuation of a floating barrier, computer equipment and a readable storage medium. The method comprises the following steps: acquiring sound path distance differences of noise diffraction paths passing through the floating barrier in multiple directions; according to the sound path distance differences of the noise diffraction paths in the multiple directions, noise attenuation items in the multiple directions passing through the floating barrier are obtained; according to the reciprocals of the noise attenuation items in the multiple directions, a noise comprehensive barrier attenuation item diffracted through multiple paths of the floating barrier is obtained; and according to the noise comprehensive barrier attenuation item, obtaining the total sound pressure level of the noise source after multi-path diffraction attenuation of the floating barrier. The sound pressure level obtained after noise attenuation and calculated through the method is accurate.

This application discloses a novel noise reduction structure for a pressure cooker, comprising: a noise reduction seat with openings at both the top and bottom, and a noise reduction cover that can be opened and closed and is disposed above the noise reduction seat. The noise reduction seat and the noise reduction cover are fitted together to form a receiving cavity covering the pressure vent cap. The noise reduction cover has a vent hole, and the inner sidewall of the noise reduction cover protrudes towards the receiving cavity corresponding to the position of the vent cap, forming a reflux wall. This embodiment, through the enveloping receiving cavity formed by the noise reduction seat and the noise reduction cover, completely covers the pressure vent cap within a closed space, forming a physical barrier layer to directly weaken noise propagation. Simultaneously, the reflux wall forces steam to swirl downwards, reducing steam velocity and impact energy before it is discharged outwards through the vent hole. This dual effect attenuates high-frequency impact noise by over 40%, and the compact integrated structure avoids the volume defects of traditional screw-on devices.

The invention relates to an acoustic insulation panel (1) based on Helmholtz single-cavity resonators, designed to effectively attenuate low-frequency noise generated by industrial equipment. The panel (1) is formed by a front wall (2) and a rear wall (3), both U-shaped, enclosing a hollow space (4) that acts as a resonator cavity. The shorter sides (2', 3') of these walls are folded inwards, forming channels that function as inlets (5) to the resonator. Furthermore, an acoustic insulation system composed of several of these panels (1) is described, in which the panels are arranged so as to allow both ventilation and noise attenuation. The associated acoustic insulation method consists of facing the resonators to maximize noise absorption at specific frequencies, ensuring a laminar air flow that improves the efficiency of the system without the need for large volumes or additional silencers.

The invention relates to an apparatus for noise attenuation in an impact pile driving device wherein the apparatus comprises a pile guide being attachable to the lower end of a hammer of an impact pile driving device. The apparatus according to the invention comprises compressing arrangement in connection with the pile guide having at least one compressing element and mechanical, hydraulic or pneumatic compressing means for compressing a pile fitted in to the pile guide transversally by means the at least one compressing element. The invention relates also an impact pile driving device and a method for noise attenuation in an impact pile driving device.

The utility model relates to related technical field of bridge engineering especially, and it is a kind of noise reduction bridge expansion joint, including receiving part, clamping groove, U type damping rubber part, connecting section bar, noise reduction layer, end connecting piece and elastic part, two groups are oppositely equipped with receiving part, the clamping groove is opened in receiving part inside, U type damping rubber part is equipped with between the two groups receiving part in cooperation with clamping groove, the connecting section bar is filled in U type damping rubber part both sides, the noise reduction layer is integrally formed with U type damping rubber part upper layer part.The utility model is through the composite structure of upper microperforation layer, honeycomb core layer and lower microperforation layer, and upper and lower microperforation layer carries out reflection and preliminary absorption to high frequency noise by the micro hole of staggered distribution, and the hexagonal hollow structure of honeycomb core layer provides multiple scattering path for noise, substantially consumes low frequency noise energy, realizes multi-band noise attenuation, significantly improves bridge periphery sound environment.

An additively manufactured noise attenuation panel (3500) for a structure within an aircraft structure includes a plurality of unit cells, each including a central body interconnected via a plurality of tubes extending from the central body. The noise attenuation panel may include an increasing wall thickness in a desired direction. A layers (3551; 3552) of unit cells may be manufactured in a twisted orientation with respect to an immediately adjacent layer (3551; 3552) of unit cells. Layers of unit cells may be manufactured in a rounded or bent orientation with respect to a central axis (3594). The noise attenuation panel may further comprise a disk and a blended transition located at the interface between the disk and an interior surface of a unit cell.

The invention discloses a fetal heart sound small signal processing method, device, equipment and medium, and relates to the technical field of data processing.The fetal heart sound small signal processing method comprises the steps that ultrasonic echo signals, monitored by a fetus-voice meter, of the fetal heart of a fetus in a pregnant woman of 9 weeks to 14 weeks of pregnancy are obtained, the ultrasonic echo signals are converted into electric signals, and to-be-processed electric signal data are obtained; performing data self-correlation processing on the to-be-processed electric signal data according to a preset data self-correlation calculation condition to obtain a self-correlation coefficient; sequentially performing bottom noise attenuation processing, frequency shift processing and envelope calculation processing on the to-be-processed electric signal data to obtain preprocessed electric signal data; and determining a signal amplification factor according to the pre-processed electric signal data and the autocorrelation coefficient, performing data amplification processing on the pre-processed electric signal data based on the signal amplification factor to obtain amplified electric signal data, and then taking the amplified electric signal data as the processed fetal heart sound small signal. And the fetal heart sound can be clearly and accurately played when the device measures the fetus in the small gestational week.

A wearable audio device can include at least one speaker to provide an initial audio output signal; at least one sensor arranged to: sense at least one characteristic of the initial audio output signal, sense noise external to the wearable audio device, and provide at least one sensor signal related to at least one characteristic of the sensed initial audio output signal and at least one characteristic of the sensed noise; at least one input arranged to accept an input related to a desired level of attenuation of the noise; a processor arranged to: receive the at least one sensor signal and the selected desired level of attenuation, select at least one coefficient from a coefficient table based on the at least one sensor signal or the selected desired level of attenuation, and provide an attenuation signal related to the selected at least one coefficient; and at least one filter arranged to receive the attenuation signal from the processor and produce a filtered audio signal based on the attenuation signal, wherein the at least one speaker is configured to provide an attenuated audio output based on the filtered audio signal.

A method that includes determining a level of sound within an acoustic environment captured by a microphone; receiving, from a headset worn by a user, data indicating an audio processing mode in which the headset is operating; determining a level of attenuation of the sound based on the audio processing mode and the level of sound; estimating sound exposure based on at least the level of attenuation and the level of sound; and transmitting the sound exposure to an application program.

Various illustrative systems, devices, and methods for face masks are provided. In general, a face mask is configured to provide cooling therapy to a user wearing the face mask. In an exemplary implementation, the face mask includes a thermoelectric cooling device, such as a Peltier device, a thermoelectric cooler (TEC), or other thermoelectric cooling device. The face mask includes a fan configured to blow air configured to dissipate the heat created by the thermoelectric cooling device. The face mask includes a noise attenuation system configured to attenuate the generated noise that is radiated into the environment, and thus, heard by the user due to use of the fan.

The invention relates to a mask with noise attenuation. Various illustrative systems, devices, and methods for a mask are provided. Generally, the mask is configured to provide cooling therapy to a user wearing the mask. In an exemplary embodiment, the mask includes a thermoelectric cooling device, such as a Peltier device, a thermoelectric cooler (TEC), or other thermoelectric cooling device. The mask includes a fan configured to blow air configured to dissipate heat generated by the thermoelectric cooling device. The mask includes a noise attenuation system configured to attenuate noise generated by the use of the fan that is radiated into the environment and thus heard by the user.

The invention belongs to the technical field of house decoration, and particularly relates to a sound insulation wall for house decoration, which comprises a wall body base layer, a sound insulation functional layer is fixedly connected to the surface of one side of the wall body base layer, and the side, deviating from the wall body base layer, of the sound insulation functional layer is covered with a decorative surface layer; the counterweight base is fixedly arranged on the side, away from the sound insulation functional layer, of the bottom of the wall base layer, a butt joint block is fixedly arranged on one side of the counterweight base, an inner cavity is formed in the other side of the counterweight base, and the inner cavity and the butt joint block are located at the same height position and matched with each other; and the butt joint positioning mechanism comprises a threaded rod, a movable block, a clamping arm and a transverse column, and the threaded rod is assembled in the inner cavity through a bearing. According to the invention, full-dimensional dead-corner-free noise reduction is realized, the noise attenuation amplitude can be greatly improved, the construction noise can be controlled within an environmental protection standard limit value, the interference to the surrounding environment is effectively reduced, and the environmental protection compliance of construction is improved.

The table top range hood comprises a machine body and a draught fan, the machine body is provided with a first flow guide cavity, a second flow guide cavity and a third flow guide cavity which are sequentially communicated, the first flow guide cavity, the second flow guide cavity and the third flow guide cavity are arranged in a U shape, and an inlet of the draught fan is communicated with the third flow guide cavity; oil smoke is suitable for sequentially flowing through the first flow guide cavity, the second flow guide cavity and the third flow guide cavity when the fan works. According to the technical scheme, the first flow guide cavity, the second flow guide cavity and the third flow guide cavity are designed to be arranged in a U shape to form the U-shaped flow channel, the U-shaped flow channel is provided with the corner part, the flowing direction of oil smoke needs to be changed for multiple times in the conveying process, the propagation path of noise is also changed, noise attenuation is achieved, and the noise reduction effect is improved. And therefore, the noise of the table top range hood can be reduced.

The utility model discloses an insulation noise reduction structure of an extra-high voltage oil-immersed shunt reactor, which comprises a plurality of layers of insulation partition plates, a cork rubber pad, a non-adhesive laminated wood fastener, a hot-pressed polyester resin plastic laminated board fastener and a lastrum laminated wood bracket, and the two adjacent layers of insulation partition plates are separated by the cork rubber pad. And the insulating partition plate is fixed on the box wall of the extra-high-voltage oil-immersed shunt reactor through the cork rubber pad, the non-adhesive laminated wood fastener, the hot-pressed polyester resin plastic laminated board fastener and the Lushi laminated wood bracket. The insulation noise reduction structure has enough mechanical strength and certain flexibility, integrates the advantages of reliable mechanical structure, reliable insulation, noise absorption and the like, and solves the problems of high ground potential field intensity and low noise attenuation in a high-voltage line end outgoing line area. The low-noise electric reactor has the advantages of being capable of improving the ground insulation strength of the high-voltage line end and absorbing and attenuating noise, and is suitable for the design of low-noise electric reactors with the grade of 750 kV to 1100 kV.

The invention discloses an OBN shear wave leakage noise attenuation method based on curvelet domain extended filtering, and the method comprises the following steps: creating a Hilbert transform record and a time derivative record of a Z component and a time derivative record of Hilbert transform based on the shear wave data of X and Y components in OBN data, and on the basis, a transverse wave leakage matching subtraction method of curvelet domain least square extended filtering is applied, so that high-precision separation of effective information and transverse wave leakage noise is realized. Theoretical model experiment and field data processing experiment results show that the method gives consideration to the separation advantage of curvelet transformation to effective signals and shear wave leakage noise and the adaptability of extended filtering to shear wave leakage prediction errors, can significantly improve the elimination precision of shear wave leakage interference on the premise of avoiding effective signal damage, and has good application prospects. And the imaging precision of the OBN data is improved.

An acoustic panel for an aircraft providing noise attenuation over a wide frequency band by combining two resonators, and acoustic panel manufacturing method. The acoustic panel includes a rear skin, a cellular structure, an intermediate layer including perforations, a cellular structure, a cellular structure and a resistive skin including perforations. The acoustic panel combines quarter-wave resonators with Helmholtz resonators to provide noise attenuation over a wide frequency range.

This invention proposes a design method for a full-band compact hybrid EMI filter circuit based on current feedback. The method includes: constructing an electromagnetic interference test circuit to obtain the common-mode EMI spectrum required for attenuation by the PWM converter, and establishing a high-frequency equivalent circuit for the PWM converter; obtaining the optimal hybrid EMI filter topology based on the high-frequency equivalent models of active and passive EMI filter circuits and the noise attenuation characteristics of the hybrid EMI filter circuit topology; designing the active EMI filter topology and its high-frequency equivalent model based on the noise cancellation principle of the active EMI filter and the common-mode EMI spectrum; designing the active EMI filter topology based on the noise cancellation principle of the active EMI filter and the common-mode EMI spectrum; designing the passive EMI filter structure based on the common-mode EMI noise spectrum after adding the active EMI filter; and designing the hybrid EMI filter circuit based on the hybrid EMI filter topology, the active EMI filter topology, the passive EMI filter structure, and the high-frequency equivalent models of the active and passive EMI filter circuits.

The application relates to a noise analysis method, in particular to a noise reduction analysis method and system based on urban green land form. The method comprises the following steps: obtaining three-dimensional data of a target green land, and determining three-dimensional form data corresponding to the target green land according to the three-dimensional data, wherein the three-dimensional form data corresponding to the target green land comprises spatial geometric form of the target green land and vegetation three-dimensional form data corresponding to the target green land; constructing a sound propagation-vegetation attenuation coupling model based on the three-dimensional form data; the sound propagation-vegetation attenuation coupling model is used for predicting expected noise at a target position according to a noise source and three-dimensional form data of the target green land; and noise at the target position is predicted based on the sound propagation-vegetation attenuation coupling model, so as to realize high-precision noise attenuation result prediction according to the three-dimensional form of the urban green land, and provide reliable data support for maintenance or planning of the target green land.