6936results about "Sound producing devices" patented technology

A controller configured to control a sound producing module includes a volume controlling unit configured to determine a demodulation amplitude and a modulation amplitude corresponding to a target volume. The sound producing module comprises a driving circuit and an air-pulse generating device. The driving circuit generates a demodulation driving signal according to the demodulation amplitude and generates a modulation driving signal according to the modulation amplitude, so as to drive the air-pulse generating device. The air-pulse generating device produces sound via generating a plurality of air pulses at an ultrasonic pulse rate.

The technology described herein is directed towards resonators that incorporate or are closely coupled to transducers from which energy is harvested. The resonators can be unit cells of a metasurface configured for narrowband sound absorption by phase cancellation of the acoustic wave Electroacoustic transducers such as piezoelectric transducers can be positioned, e.g., at the neck ports of the resonators, to generate electricity as the air pressure of incoming acoustic waves enters the unit cells. Energy can be harvested from the electricity, and stored for usage and / or used directly to power a device. Such a device powered by the harvested energy can change the resonant frequency of the device, e.g., by changing temperatures in the resonators' air cavities, changing respective dimensions of the respective air cavities, or changing the resonant frequency of the unit cells resonators by changing respective airflow in the respective air cavities.

The invention provides an acoustic vortex tunneling transmission method based on topology pairing metasurfaces, and the method comprises the steps: respectively arranging an absorption type metasurface and an emission type metasurface which have opposite topological charges at an inlet and an outlet of a tunneling channel, forming a pair of topology pair TPMs structures, and forming a vortex tunneling system together with a sub-wavelength channel; mode conversion between vortex waves and plane waves is achieved through multi-period fan-shaped grooves etched in the angular direction and the radial direction, and the transmission efficiency is enhanced through Fabry-Perot resonance in a sub-wavelength channel. When the length of the tunneling channel meets specific conditions, periodical adjustment of transmissivity and perfect tunneling can be achieved, and the tunneling structure has high OAM mode coupling and transmission efficiency while guaranteeing the compact structure and low material cost. The metasurface designed by the invention supports diversified acoustic vortex tunneling transmission along a straight line and a curve, and shows excellent flexibility and stability.

The technology described herein is directed towards a metasurface arranged with unit cells for broadband and / or multiband sound absorption, in which the unit cells are based on the principles of Helmholtz resonators. Deeply subwavelength sound absorbing unit cells are designed and constructed based on desired resonance frequencies. Each unit cell includes a neck portion and air chamber dimensioned to resonate at a desired resonance frequency and thereby inverse phase cancel corresponding frequencies of incoming sound waves. Differently designed and arranged subgroups of unit cells are part of the metasurface, which can be positioned proximate to a noise source. As practical examples, the metasurface or multiple metasurfaces can be placed near or wrapped around a computer server or rack of servers to absorb fan noise. The metasurface components (including the unit cells) can be printed by a 3D printer to result in a thin, light-weight, and cost effective noise absorbing metasurface.

------ Acoustic Enclosure and Method for Leveling an Acoustic Enclosure The present invention relates to an acoustic enclosure (20) comprising a loudspeaker (21) mounted flush on a front face of the enclosure (20), characterized in that at least one Helmholtz resonator (26) is formed on the front face of the enclosure (20) between each lateral edge of the front face and the loudspeaker (21), the at least one Helmholtz resonator (26) being dimensioned to have a band gap to block the propagation, in the plane of the front face of the enclosure (20), of acoustic waves in the useful frequency band of the loudspeaker (21). Figure to be published with the abstract: Figure 6a

The technology described herein is directed towards a metasurface arranged with unit cells for narrowband sound absorption, in which the unit cells are based on Helmholtz resonators that can have their resonant frequencies adjusted via MEMS actuators. A sound absorbing unit-cell is designed and constructed based on a general resonance frequency, and includes a neck portion and air chamber dimensioned to resonate close to the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. A bimorph MEMS actuator and / or moveable part in the resonators, controlled by a controller, facilitates changing of the airflow the unit cells to adjust the resonant frequencies thereof, to cancel acoustic waves of different frequencies corresponding to noise, which can change over time. The unit cells can be distributed as part of a metasurface, which can be positioned proximate to a noise source to phase cancel the noise.

In aspects of ending audio playback based on a trigger word, a mobile device implements an audio playback manager that detects a headset in communication with a mobile device, the headset causing active noise cancellation (ANC) and outputting audio playback communicated from the mobile device. The audio playback manager detects a trigger word that is audible in an environment of the mobile device. In response to detecting the trigger word, the audio playback manager ends the audio playback and adjusts the ANC of the headset.

The invention discloses a frequency mixing sound demodulator based on a curled structure and a use method thereof in the acoustics field, the demodulator is used for separating frequency mixing sound mixed by a plurality of sound waves with preset frequencies according to respective frequencies, and the demodulator comprises an air waveguide for transmitting the sound waves, and blocking structures arranged on two sides of the air waveguide for blocking the sound waves from penetrating, and a plurality of curled structures that capture corresponding preset frequency sound waves; curled structures are arranged in the barrier structure on at least one side of the air waveguide at intervals, one end of each curled structure is open, and the other side is closed; a plurality of cross beams for blocking penetration of sound waves are arranged in each curled structure, and an internal channel of each curled structure is divided into different lengths to serve as different acoustic resonant cavities so as to capture the sound waves with different frequencies; the closed end of each curled structure is a detection end of each preset frequency sound wave. The invention solves the problem that the existing method is difficult to instantly separate the frequency mixing sound signal and carry out information transmission.

A calibration method comprises adjusting an operating frequency of an air-pulse generating device, such that a sound pressure level (SPL) of the air-pulse generating device is within a specific range. The sound producing module comprises the air-pulse generating device configured to produce sound via generating a plurality of air pulses at a pulse rate corresponding to the operating frequency.

The invention discloses a real-time noise reduction method and system supporting Bluetooth audio interaction, and the method comprises the steps: collecting an environment audio signal and a Bluetooth interaction audio signal, and carrying out the timestamp alignment and spatial calibration of the environment audio signal and the Bluetooth interaction audio signal; an improved multivariate variational mode decomposition algorithm is adopted to decompose and extract noise features, the noise features are combined with user historical noise data, a dynamic noise model is constructed through a long-short-term memory network, parameters are updated in real time, Bluetooth interaction audio content features and a user behavior data recognition scene are analyzed, and a noise reduction strategy is determined. And according to the dynamic noise model and the scene result, reinforcing learning to optimize filter parameters, generating a directional anti-noise signal to carry out noise reduction on the Bluetooth interaction audio signal, collecting the noise reduction intensity manually adjusted by a user, calculating voice definition and total harmonic distortion, and carrying out noise reduction on the Bluetooth interaction audio signal. And inputting a feedback and evaluation result into the modeling and noise reduction steps, carrying out dynamic range adjustment, sound channel balance and power amplification on the audio after noise reduction, and outputting the audio through a loudspeaker.

The invention discloses an intelligent noise reduction method and system based on a mine earphone, and the method comprises the following steps: S1, obtaining an original noise signal in a mine operation environment, and carrying out the preprocessing of the original noise signal; s2, designing an adaptive compensation mechanism according to the reflection characteristics of the closed space of the mine, calculating a sound wave propagation attenuation coefficient and reflection delay, constructing a roadway reverberation model, and generating advanced compensation sound waves; and S3, carrying out collaborative fusion on the advanced compensation sound wave and a main noise reduction signal to generate a composite noise reduction signal. The invention relates to the technical field of intelligent noise reduction. According to the intelligent noise reduction method and system based on the mine earphone, the noise level in a mine operation environment is effectively reduced, the communication efficiency and the working comfort of operators are improved, potential damage of noise to hearing of the operators is reduced, and therefore the overall safety and the production efficiency of mine operation are improved.

The invention provides a noise reduction method and device, equipment and a medium, weighting processing is performed on a first time domain reference noise signal vector to obtain a second time domain reference noise signal vector, a sampling point closer to the current moment is endowed with a higher weight, the noise reduction performance is optimized, and the noise reduction performance is improved by updating a weight coefficient and the second time domain reference noise signal vector. Therefore, the noise cancellation signal is determined on the time domain, filtering on the time domain is realized, the noise cancellation signal is generated to carry out noise reduction processing on the primary noise in the target noise reduction area, extra time delay caused by frequency domain filtering is avoided, noise reduction time delay is reduced, and the filtering effect is improved. The updating process of the weight coefficient is completed in the frequency domain, updating is achieved in the frequency domain with smaller blocks, the calculation amount is reduced, the interval time of noise reduction processing is shortened, the calculation efficiency of the algorithm is improved, the processing delay is reduced, and the noise reduction effect is improved.

The invention discloses a noise reduction method and device, equipment, a storage medium and a program product, and relates to the technical field of audio processing, and the method comprises the steps: collecting a bone conduction signal and at least two paths of environment air conduction signals of an earphone wearer through an earphone, based on the bone conduction signal, performing first noise reduction processing on a target air conduction signal of a target direction determined based on the at least two paths of environment air conduction signals to remove a first air conduction component of a relatively low frequency band of an earphone wearer, and obtaining an initial noise-reduced signal; and performing second noise reduction processing on the initial noise-reduced signal based on the bone conduction signal, the at least two paths of environmental air conduction signals and the phase difference of the at least two paths of environmental air conduction signals, so as to remove a second air conduction signal of a higher frequency band of the earphone wearer, and obtain a target noise-reduced signal. According to the method and the device, the noise generated by the earphone wearer in the audio recorded by the earphone is effectively removed.

An acoustic matching structure is used to increase the power radiated from a transducing element with a higher impedance into a surrounding acoustic medium with a lower acoustic impedance. The acoustic matching structure consists of a thin, substantially planar cavity bounded by a two end walls and a side wall. The end walls of the cavity are formed by a blocking plate wall and a transducing element wall separated by a short distance (less than one quarter of the wavelength of acoustic waves in the surrounding medium at the operating frequency). The end walls and side wall bound a cavity with diameter approximately equal to half of the wavelength of acoustic waves in the surrounding medium. In operation, a transducing element generates acoustic oscillations in the fluid in the cavity. The transducing element may be an actuator which generates motion of an end wall in a direction perpendicular to the plane of the cavity to excite acoustic oscillations in the fluid in the cavity, and the cavity geometry and resonant amplification increase the amplitude of the resulting pressure oscillation. The cavity side wall or end walls contain at least one aperture positioned away from the center of the cavity to allow pressure waves to propagate into the surrounding acoustic medium.

The technology described herein is directed towards a metasurface arranged with unit cells for narrowband sound absorption, in which the unit cells are based on Helmholtz resonators that can have their resonant frequencies adjusted via a shared tuning element, e.g., a screw, or a piezoelectric actuator. A sound absorbing unit-cell is designed and constructed based on a general resonance frequency, and includes a neck portion and air chamber dimensioned to resonate close to the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. Collectively moveable floors in the resonators facilitate changing the resonators' air cavity dimensions, to adjust the resonant frequencies to cancel acoustic waves of different frequencies corresponding to noise, which can change over time. The unit cells can be distributed as part of a metasurface, which can be positioned proximate to a noise source to phase cancel the noise.

In aspects of presenting relevant audio data, a mobile device implements an audio playback manager that monitors audio in an environment for a trigger word. The audio playback manager detects the trigger word via a microphone associated with a headset in communication with a mobile device. The audio playback manager determines whether a portion of the audio preceding the trigger word is relevant to a user of the mobile device and presents the portion of the audio that is relevant to the user.

A refuse vehicle includes a body coupled at least one of the frame and the chassis, a battery configured to provide electrical power to a first motor, a vehicle body supported by the chassis and defining a receptacle for storing refuse therein, an electric power take-off system coupled to the vehicle body, the electric power take-off system including a second motor configured to convert electrical power received from the battery into hydraulic power, one or more microphones coupled to the body and configured to detect noise, one or more speakers coupled to the body configured to emit noise reducing sounds, and a controller configured to receive data related to the detected noise from the one or more microphones and cause the one or more speakers to emit the noise reducing sounds in response to the data received from the one or more microphones.

The invention belongs to the technical field of low-frequency sound absorption, and discloses a micro-perforated plate composite gradient spiral pipe sound absorption device and method.The micro-perforated plate composite gradient spiral pipe sound absorption device comprises a variable cross-section spiral pipe, and the diameter of the inlet end of the variable cross-section spiral pipe is larger than that of the outlet end of the variable cross-section spiral pipe; a plurality of MPP plates are mounted in the variable-cross-section spiral pipe, one MPP plate is embedded into the inlet end of the variable-cross-section spiral pipe, and the other MPP plates are sequentially embedded into the variable-cross-section spiral pipe at equal intervals, so that a multi-stage MPP plate composite sound absorption structure is formed; and the cross-section pipe diameter of the variable cross-section spiral pipe is linearly reduced from the inlet end of the variable cross-section spiral pipe to the outlet end of the variable cross-section spiral pipe. Through the gradient design of the variable cross-section spiral tube integrated micro-perforated plate, low-frequency broadband efficient sound absorption is realized in a compact space, the problem of heavy structure caused by dependence on a deep and large back cavity in the traditional technology is avoided, the limitation of narrow sound absorption frequency band is overcome, and the sound absorption device is particularly suitable for being applied to occasions with limited spaces and has wide application prospects. And low-frequency performance and broadband characteristics are considered in a limited space.

The invention provides an attenuator for ducted air flow systems such as heating, ventilation and air conditioning systems arranged to direct the airflow into the attenuator by reducing the airflow path geometry into a central channel surrounded by absorbing material to damp resonant modes to reduce noise more uniformly across the desired frequency spectrum than resistive attenuators.

The invention discloses an assembly type efficient sound insulation cover convenient to install, and relates to the technical field of sound insulation covers. Comprising a plurality of pieces of main body square steel, the main body square steel are linearly and evenly distributed at equal intervals, jacking mechanisms used for improving the bottom supporting strength are arranged on the inner walls of the main body square steel correspondingly, and assembly type connecting mechanisms used for improving the connecting strength and stability are installed in the main body square steel correspondingly; according to the assembly type efficient sound insulation cover convenient to install, main body square steel is inserted and limited in a penetrating and inserting mode through the assembly type connecting mechanism, the defect that limiting performance is insufficient due to the fact that a lap joint mode is directly used in a traditional structure is overcome, the whole assembly process is simpler and more convenient, rubber pads and expansion water stop strips are arranged at splicing joints, and the assembly efficiency is improved. The vibration transmission of equipment can be blocked, the inherent frequency is kept away from the vibration frequency of the equipment, secondary noise caused by resonance is avoided, meanwhile, through gaps are reduced, the noise is prevented from leaking from the insertion hole position, and the problem of noise leakage is solved.

The invention relates to the technical field of energy storage and noise reduction, and discloses an active and passive combined energy storage and noise reduction system which comprises a passive noise reduction subsystem and an active noise reduction subsystem which are arranged on a cabinet body, the passive noise reduction subsystem is used for prolonging an exhaust path of air at an air outlet in the cabinet body and reducing noise of the air at the air outlet, and the active noise reduction subsystem is used for reducing noise of the air at the air outlet. The active noise reduction subsystem is used for actively outputting a reverse sound wave signal for active noise reduction; according to the standard requirements of environmental noise, the exhaust noise of the cabinet body can be reduced through the passive noise reduction subsystem, or the exhaust noise of the cabinet body can be reduced through the combination of the passive noise reduction subsystem and the active noise reduction subsystem. According to the invention, passive and active combined noise reduction or passive noise reduction can be carried out on the energy storage cabinet according to the environmental noise standard, so that the energy storage cabinet can be allowed to be used in different scenes, the occupied space is saved, and the response speed is high.

The technology described herein is directed towards a metasurface arranged with unit cells for narrowband sound absorption, in which the unit cells are based on Helmholtz resonators that can have their resonant frequencies adjusted via actuators, e.g., piezoelectric motors. A sound absorbing unit-cell is designed and constructed based on a general resonance frequency, and includes a neck portion and air chamber dimensioned to resonate close to the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. Moveable partitions in the resonators, controlled by piezoelectric actuators, facilitates changing of the resonators' air cavity dimensions, to adjust the resonant frequencies to cancel acoustic waves of different frequencies corresponding to noise, which can change over time. The unit cells can be distributed as part of a metasurface, which can be positioned proximate to a noise source to phase cancel the noise.

Apparatus for retrieving an acoustic room information from a database, comprising: a test fingerprint processor (10) for deriving a test fingerprint from a test acoustic room information; and a database processor (20) for retrieving a reference acoustic room information having a reference fingerprint matching with the test fingerprint, wherein the test fingerprint processor (10) comprises; a filter bank configured for decomposing the test acoustic room information into a plurality of acoustic room information sub-bands; and a parameter calculator (12) configured for calculating a sub-band parameter for each acoustic room information sub-band of the plurality of acoustic room information sub-bands, the sub-band parameter indicating an energy change over time in the acoustic room information sub-band, wherein the test fingerprint is based on the sub-band parameters for the acoustic room information sub-bands.

The invention discloses a digital audio processing system based on a DSP, and relates to the field of digital audio processing, and the system comprises an acquisition module which is used for capturing vehicle body vibration sound waves, environment incoming noise and in-cabin original audio signals, and generating a multi-dimensional acoustic data stream through voiceprint feature extraction so as to output an original sound signal matrix; the analysis module is used for mapping the original sound signal matrix to a phase space, extracting singular attractor features of noise evolution through a chaos theory, and generating a noise dynamic model; according to the method, various sound waves can be accurately captured and converted into multi-dimensional data, deep analysis and targeted counteracting of noise are achieved on the basis, meanwhile, an acoustic adjustment scheme matched with the environment in the cabin can be generated, the acoustic environment can be dynamically optimized in combination with the physiological state of passengers, and potential noise is pre-judged in advance for suppression.

The invention discloses a track noise control method and system based on active acoustic control, and the method comprises the steps: collecting a track noise signal through a sensor array, and processing the signal through Fourier transform to obtain a spectrum distribution characteristic; judging the type of a noise source according to the spectral distribution characteristics, if the spectral distribution shows high-frequency dominance, determining the noise as wheel-rail contact noise, and if the spectral distribution shows low-frequency dominance, determining the noise as rail vibration noise, and obtaining a noise source contribution proportion; according to the noise source contribution proportion, a dynamically adjusted control signal is obtained; acquiring noise source coupling information which changes in real time from the dynamically adjusted control signal, and determining a fused noise source model; according to the fused noise source model, a least square method is adopted to optimize a control strategy, and an optimized control instruction sequence is obtained; and according to the optimized control instruction sequence, acquiring matching data of the current operation density and speed, and if the effect does not reach the standard, iteratively updating the model to obtain final control output.

The invention belongs to the technical field of earphone noise reduction, and provides a noise reduction regulation and control method for an earphone and a noise reduction earphone. The method comprises the following steps: acquiring a first environment sound signal of an environment area, and extracting human voice features from the first environment sound signal to construct a human voice feature template library; in response to a noise reduction regulation and control instruction, collecting a second environment sound signal of the environment area, converting the time domain signal into a frequency domain signal through Fourier transform, and extracting a frequency spectrum feature from the frequency domain signal; performing matching calculation on the spectrum features and a human voice feature template library to determine environment voice signals, human voice signals and noise signals; an active noise reduction algorithm is adopted to generate offset sound waves opposite to the noise signals in phase, the human voice signals are amplified, and the offset sound waves and the amplified human voice signals are output through a loudspeaker of the earphone. According to the invention, effective noise filtering and clear transparent transmission of specific human voice are realized, smooth communication can be realized without taking off the earphone, and the use experience is improved.