3728results about How to "Improve noise reduction" patented technology

To achieve vibration-dependent noise reduction by the use of a microphone to pick up an audio signal and a vibration sensor. The microphone apparatus according to a preferred embodiment of the present invention is one having one or more microphone, one or more sensor, noise extraction means for extracting the noise bandwidth section from the output signal of the sensor, an adaptive filter coordinated with the microphone for receiving the output signal of the noise extraction means as the reference input signal, and an adder for subtracting the output signal of the adaptive filter from the output signal of the microphone, wherein the vibration detection directions of the microphone and the sensor match, and so do the output polarities of the vibration signal.

A noise control device according to the present invention is capable of reducing noises respectively arriving in a plurality of spaces which are acoustically independent from each other. The noise control device comprises: sound output means, which are respectively provided in the plurality of spaces so as to respectively correspond to the plurality of spaces, each for outputting a sound to a corresponding space; noise detection means, which is provided in at least one of the plurality of spaces, for detecting a noise arriving in the at least one of the plurality of spaces; and signal generation means which is a single means for generating, based on the noise detected by one of the noise detection means, a cancellation signal for canceling the noise, and outputting the generated cancellation signal to each of the plurality of sound output means.

The invention is directed to an implanted microphone having reduced sensitivity to vibration. In this regard, the microphone differentiates between the desirable and undesirable vibration by utilizing at least one motion sensor to produce a motion signal when an implanted microphone is in motion. This motion signal is used to yield a microphone output signal that is less vibration sensitive. In a first arrangement, the motion signal may be processed with an output of the implantable microphone transducer to provide an audio signal that is less vibration-sensitive than the microphone output alone. Specifically, the motion signal may be scaled to match the motion component of the microphone output such that upon removal of the motion signal from the microphone output, the remaining signal is an acoustic signal.

A noise reducing apparatus is disclosed, which includes: input means for inputting multiple audio signals from multiple audio channels; multiple band extracting means for extracting a predetermined band from the multiple audio signals; calculating means for averaging signals from the multiple band extracting means; multiple first level detecting means for detecting the signal levels in a predetermined period of time of the signals from the multiple band extracting means; second level detecting means for detecting the signal level in a predetermined period of time of the signal from the calculating means; selecting means for selecting, for each of the predetermined period of times, the signal having the lowest level value of the level values detected by the multiple first level detecting means and the second level detecting means; band limiting means for limiting the band of the signal from the selecting means; and band synthesizing means for band-synthesizing the signal from the band limiting means and the signal in a band, which is not extracted by the multiple band extracting means, for each audio channel, wherein the output of the band synthesizing means is an audio channel output signal.

The invention relates to an active noise reducing method and an active noise reducing device, in particular to active noise reduction for noise generated by importing and exporting wind gate of electrical equipments. The characteristics of amplitude, frequency and phase of noise of noise source are detected through sampling the noise signal. A signal with the same amplitude and reverse phase is generated through filtering and anti-phase processing and output through a speaker to counteract the noise signal so as to achieve the object of noise reduction, wherein the filtered signal is modified adaptively during filtering process so that the filtered signal is closer to the noise source signal while filtering the noise, thus the effect of noise reduction is more ideal.

The invention relates to a time-space domain hybrid video noise reduction device and a time-space domain hybrid video noise reduction method, and belongs to the technical field of video image processing. The device comprises a time domain noise reduction module, a smoothing coefficient storage module, a reference frame storage module and a space domain noise reduction module. The method comprises the following steps that: the time domain noise reduction module calculates noise variance, the motion intensity of a current point and a weighting coefficient of the current point according to the current point and a reference point; the time domain noise reduction module calculates and stores a smoothing coefficient of the current point and a time domain filtering result of a current frame respectively; and the space domain noise reduction module performs space domain filtering to obtain noise-reduced image data. Therefore, the combined application of time domain noise reduction and space domain noise reduction is realized, a good noise reduction effect can be achieved, system overhead required by the noise reduction can be effectively reduced, and system cost is lowered. The noise reduction device is simple in structure; and the noise reduction method can be conveniently and widely applied.

The invention provides a method for executing active noise reduction for an earphone in an electronic terminal and an electronic terminal thereof. The method comprises: (A), detecting a type of an earphone connected with an electronic terminal; (b), setting an active noise reduction parameter according to a detection result; and (C), on the basis of the set active noise reduction parameter, generating a noise reduction signal for eliminating environment noises and outputting the noise reduction signal by the earphone. According to the method and the electronic terminal, proper active noise reduction parameters can be set according to various earphones, so that good noise reduction effects can be relized for various earphones.

The invention provides a liner and a liquid heating container. The liner comprises a body, a heat conduction plate and a heating part, wherein the body comprises a barrel body and a barrel bottom connected with the bottom of the barrel body; the heat conduction plate fits to the outer wall face of the barrel bottom, and the heat conduction coefficient of the heat conduction plate is greater than that of the barrel bottom; the heating part is ring-shaped and fits to the lower surface of the heat conduction plate, and the projection of the heating part is positioned in the heat conduction plate;the thickness of the heat conduction plate is greater than or equal to 2mm; and / or, a spacing between the outer periphery of the contact part of the heating part and the heat conduction plate and theouter periphery of the heat conduction plate is greater than or equal to 3mm. For the liner provided by the invention, by increasing the spacing between the outer periphery of the contact part of theheating part and the heat conduction plate and the outer periphery of the heat conduction plate, heat generated by the heating part becomes bidirectional heat conduction from unidirectional heat conduction, so that the local thermal power density is greatly reduced, and the noises caused by heating water are reduced; and / or, the heat conduction plate is thickened, so that the local thermal shockis prevented, heat is uniformly transmitted as far as possible, and further, the noises caused by heating water are reduced.

The invention is directed to an implanted microphone having reduced sensitivity to vibration. In this regard, the microphone differentiates between the desirable and undesirable vibration by utilizing at least one motion sensor to produce a motion signal when an implanted microphone is in motion. This motion signal is used to yield a microphone output signal that is less vibration sensitive. In a first arrangement, the motion signal may be processed with an output of the implantable microphone transducer to provide an audio signal that is less vibration-sensitive than the microphone output alone. Specifically, the motion signal may be scaled to match the motion component of the microphone output such that upon removal of the motion signal from the microphone output, the remaining signal is an acoustic signal.

A baffle for use in a sound suppressor for a firearm utilizing proximal and distal faces with at least one joining wall positioned between the proximal and distal faces, and forming two expansion chambers between the proximal and distal faces. The joining wall has a bore hole and at least one opening in the wall itself and at least one opening from the bore hole into at least one of the expansion chambers positioned between the proximal and distal faces of the baffle. The joining wall may be either curvilinear, curvilinear stepped, planar or angled in shape. Openings are provided on the proximal face and the distal face of the baffle. At least one face of the baffle is either flat, curvilinear, curvilinear stepped, or asymmetrical to the axis of the baffle.

An acoustic resonance device is installed in a compartment of a vehicle so as to reduce a low-frequency sound pressure (or noise) dependent upon a natural vibration. Specifically, an acoustic resonance device is a panel / diaphragm resonator, a resonance pipe, or a Helmholtz resonator, the inner space of which communicates with the compartment via an opening. The acoustic resonance device is positioned in proximity to an antinode of sound pressure owing to a natural vibration occurring in a driver / passenger space inside the compartment. Alternatively, the acoustic resonance device increases a particle velocity at a specific natural frequency or decreases sound pressure at an excitation frequency which occurs due to an external condition of the vehicle. The acoustic resonance device can be installed in a roof, a seat, a pillar supporting the roof, or a door of a vehicle.

Systems and methods of improved noise reduction using direction of arrival information include: receiving an audio signal from two or more acoustic sensors; applying a beamformer module to employ a first noise cancellation algorithm to the audio signal; applying a noise reduction post-filter module to the audio signal, the application of which includes: estimating a current noise spectrum of the received audio signal after the application of the first noise cancellation algorithm; using spatial information derived from the audio signal received from the two or more acoustic sensors to determine a measured direction-of-arrival by estimating the current time-delay between the acoustic sensor inputs; comparing the measured direction-of-arrival to a target direction-of-arrival; applying a second noise reduction algorithm to the audio signal in proportion to the difference between the measured direction-of-arrival and the target direction-of-arrival; and outputting a single audio stream with reduced background noise.

The invention relates to a sound-insulating, ventilating and heat transfer enhancing acoustic metamaterial structural unit, which comprises a frame, wherein a restraining body is arranged inside the frame, and at least one of the upper and lower surfaces of the frame is coated with a thin film; and at least one hole is formed in the restraining body and the thin film. In addition, the invention provides an acoustic metamaterial composite plate and an acoustic metamaterial composite structure comprising the acoustic metamaterial structural unit, as well as a frequency modulation method and an assembly method. The acoustic metamaterial structural unit has sound insulation capability superior to that of an ordinary perforated plate or micro-perforated plate within a broadband, can ensure that sufficient heat flow, air flow or liquid flow can pass through smoothly, and increases heat diffusion rate of fluid media on both sides of holes and accelerates heat convection efficiency through unit localized vibration generated by the structure under excitation of acoustic waves. The acoustic metamaterial structural unit and the array composite structure have the advantages of simple assembly technology and stable working performance.

A hydroelectric generating set vibration signal noise reduction method based on mode autocorrelation analysis of SVD and VMD comprises the steps of constructing a Hankel matrix of a set vibration signal and performing singular value decomposition (SVD), selecting an effective singular value based on a mean value filtering strategy for reconstructing the signal, and realizing pre-filtering; performing decomposition through variational mode decomposition (VMD) for obtaining a series of mode functions, calculating an autocorrelation function of each mode component, selecting effective mode components according to an energy set of the autocorrelation function, and obtaining a signal after noise reduction through adding all effective mode components. According to the hydroelectric generating set vibration signal noise reduction method provided by the invention, a noise reduction experiment is carried out through simulation analysis and actual measurement of a vibration signal; and a result represents a fact that the method has relatively high noise reduction performance and can effectively improve hydroelectric generating set vibration signal analysis precision.

The invention discloses environment-friendly diatom ooze wall material powder and a wall material as well as a preparation method and application thereof. The diatom ooze wall material with macromolecule sieve structure is prepared by taking a plurality of natural environment-friendly non-metal material having strong adsorbability and good plasticity as main materials through a simple process. The environment-friendly diatom ooze wall material powder has the advantages of low cost, air purification, moisture absorption, deodorization, inflaming retarding, heat insulation, easy popularization,and the like.

The invention discloses a wavelet transform and variable-step-size LMS (least mean square) adaptive filtering based signal denoising method which comprises the following steps that: 1, signal receiving and synchronous storage: a data processor synchronously stores received signals into a data memory so as to obtain a sampling sequence X (k) which is a one-dimensional signal; 2, high-frequency signal extraction: the data processor carries out wavelet transform on the currently received one-dimensional signal X (k) and extracts high-frequency signals; and 3, LMS adaptive filtering: the data processor invokes the high-frequency signals extracted by an LMS adaptive filter to carry out LMS error calculation so as to obtain output signals subjected to filtering, and carries out adjustment on the parameters of the filter according to error signals, so that the output signals tend to interference signals. The method disclosed by the invention is simple in steps, reasonable in design, convenient to realize, and good in denoising effect; and the denoising process is performed through the combination of wavelet transform and variable-step-size LMS adaptive filtering, so that the filtering effect and the tracking speed are effectively increased.

A silencer for a vacuum cleaner is provided and includes at least one hermetic expansion chamber mounted in an exhaust channel of the vacuum cleaner and allowing an exhaust airflow from the vacuum cleaner to pass through. The expansion chamber at its two sides has an inlet and an outlet connected to the exhaust channel. A silencing board is mounted in the expansion chamber, separating the inlet from the outlet. Pores are distributed throughout in the silencing board. The silencer integrates several different silencing structures together, and, when mounted to the exhaust port of the vacuum cleaner, can considerably diminish the noise generated by the vacuum cleaner in operation.

The invention discloses a SEBS thermoplastic elastic floor, which comprises the following parts: 100wt% SEBS resin and modifier, 75-125wt% rubber filling oil, 20-60wt% polypropylene, 200-400wt% mineral filler, 0.8-1.2wt% lubricant and 0.45-0.70% aging retarder. The making method comprises the following steps: weighing raw material; blending; graining; squeezing; moulding; obtaining the product with anti-slip, abrasion-proof, noise reduction and weather resistant property; fitting for paving basic ground to replace plastic or rubber floor material.

An air blower apparatus is provided including a hub which is a center of rotation, and a plurality of blades disposed along an outer peripheral surface of the hub and having leading and trailing edges and where both an outer peripheral end of the leading edge and an outer peripheral end of the trailing edge lie ahead relative to the rotative direction. An outer peripheral part of the blade may be bent toward the suction side in such a way as to form a starting point at which an airflow starts leaking, and the radial-direction width, W, of the bent part gradually increases from the vicinity of the leading edge to the vicinity of the trailing edge. A blade tip vortex (β) generated from a blade positioned ahead relative to the rotational direction F and a separation vortex from a pressure surface of a blade positioned behind relative to the rotational direction F offset each other, so that discharge vortexes are suppressed.

The invention relates to the field of voice technologies, in particular to a self-adaptive denoising method based on sub-band noise analysis. The method includes the steps that firstly, framing and short time frequency domain transformation are conducted on input time domain audio signals with noise, and then frequency domain audio signals with noise are generated; secondly, a noise energy spectrum of the frequency domain audio signals with noise is estimated through a minimum value tracking method; thirdly, the posterior signal to noise ratio and the prior signal to noise ratio of the noise energy spectrum are calculated; fourthly, through a nonlinear gain extension method, denoising gains of all time frequency units are calculated through the posterior signal to noise ratio and the prior signal to noise ratio; fifthly, smoothing filtering is conducted on the denoising gains of all the time frequency units to reduce tone quality distortion; sixthly, the denoising gains act on all the time frequency units of the audio signals with noise in the first step, and then denoised frequency domain audio signals are acquired; seventhly, short time frequency domain inverse transformation is conducted, and then the final denoised time frequency audio signals are acquired and output. According to the method and system, stable noise in target signals can be greatly lowered.

An active noise control apparatus includes a road surface input detector, a reference signal generator, an adaptive filter, a noise-cancellation sound generator, an error detector, a reference signal corrector, a filter coefficient updating unit, a transfer characteristic variation detector, and an update amount controller. The transfer characteristic variation detector is configured to detect a variation in transfer characteristic between the road surface input detector and the error detector. The update amount controller is configured to increase an amount of updating of a filter coefficient to a value greater than a value that is used in a normal mode in accordance with the variation in transfer characteristic detected by the transfer characteristic variation detector.

A noise-canceling headphone that cancels external noise with a feedforward system includes a driver unit disposed in a housing, a microphone unit that is outwardly disposed in the housing and collects the external noise, and canceling signal generator that generates a noise-canceling signal having a phase opposite to the noise entering through the headphone. The noise-canceling headphone includes an error detecting microphone unit that detects error noise uncanceled by the feedforward system, and error noise-canceling signal generator that generates an error correction signal to cancel the error noise with a feedback system.

The invention discloses a single-channel real-time noise reduction method based on the convolutional recurrent neural network, a single-channel real-time noise reduction device based on the convolutional recurrent neural network, an electronic device and a storage medium, and belongs to the technical field of computers. The method comprises the following steps: extracting acoustic features from received single-channel voice signals, carrying out iterative operation on the acoustic features in a pretrained convolutional recurrent neural network model, thus the specific value film of the acoustic features is calculated, carrying out masking on the acoustic features by adopting the specific value film, and synthesizing the acoustic features after masking and the phase positions of the single-channel voice signals, thus obtaining voice signals. For the single-channel real-time noise reduction method based on the convolutional recurrent neural network and the single-channel real-time noisereduction device based on the convolutional recurrent neural network, the parameter number of the neural network can be reduced, the data storage amount and the demand for the system data bandwidth can be reduced, and the real-time property of the single-channel noise reduction is greatly improved while the good noise reduction property is realized.

The invention discloses an intelligent detection and quantitative recognition method for the defect of concrete. According to the method, a concrete test piece is subjected to impact echo signal sample acquisition, signal noise reduction treatment and characteristic value extraction so as to construct a recognition model for analysis components including feature extraction, defect inspection, defect diagnosis and defect quantification and positioning; and the model is used for detecting and recognizing to-be-detected concrete. The intelligent detection and quantitative recognition method provided by the invention is directed at disadvantages of conventional detection technology for concrete defects and based on theoretical analysis, value simulation and model testing, employs advanced signal processing and artificial intelligence technology and fully digs out characteristic information of a testing signal, thereby establishing the model for intelligent rapid detection and classified recognition based on wavelet analysis and an extreme learning machine; and the model has good classified recognition performance, realizes intelligent rapid quantitative recognition and evaluation of the variety, properties and scope of the defect of concrete and further improves the innovation and application level of non-destructive testing technology for the defect of concrete.

Disclosed herein is an audio outputting device for switching a plurality of processes to perform a process on an audio signal, and acoustically reproducing and outputting the audio signal, the audio outputting device including, a control section for, when changing a process performed on an audio signal from one process to another process, stopping the one process on the audio signal, outputting sound based on the audio signal unprocessed by either of the one process and the other process, and performing the other process on the audio signal after passage of a predetermined period of time.

The invention discloses a sound source direction judging device, a sound source direction judging method as well as a microphone directivity regulating system and a microphone directivity regulating method. The sound source direction judging device comprises a noise filtering unit, a direction computing unit, and a microphone array composed of three pairs of microphones symmetrically distributed in the positive and negative directions of the X axis, the Y axis and the Z axis, wherein the microphone array is used for receiving sound wave signals of a sound source, and transmitting the sound wave signals to the noise filtering unit; the direction computing unit is used for calculating direction coordinates of the sound source according to the sound wave signals with noise signals filtered out, and judging the direction of the sound source according to the direction coordinates of the sound source. A directivity regulating unit of the microphone directivity regulating system obtains the direction coordinates of the sound source calculated by the sound source direction judging device, regulates the beam direction of the microphone array so that the beam direction is towards the direction coordinates of the sound source, and controls the microphone array to only receive sound waves emitted from the sound source direction, so that voice signals are well received, good voice enhancement and noise attenuation effects are realized, and the effectiveness and reliability of speech communication are realized.

A handheld device includes: an orientation sensor; an audio processor connected to the orientation sensor and adapted to receive orientation information from the orientation sensor; and a plurality of microphones through which audio content is captured, wherein the audio processor modifies the noise reduction algorithm applied to the audio content captured based, at least in part, on the orientation information.

The invention discloses an active noise reduction method applied to a range hood. A noise reduction system using the active noise reduction method comprises a power supply system, input equipment, output equipment and a data processing module; the input equipment is connected with the data processing module; the data processing module is connected with the output equipment; the input equipment particularly comprises noise information input equipment, namely, a noise acquisition microphone array, a pre-amplification module and an ADC module; the data processing module comprises a filter, a controller W1 and a controller W2; and the output equipment comprises a loudspeaker array specially used for emitting noise reduction sound waves, a DAC module and a D type amplifier. The noise reductionsystem can be matched with system equipment according to different models of range hoods, the reusability is high and the noise reduction effect is remarkable; to solve the problem that inner equipment of the range hood is stained with oil, oil-tight films or half-funneled oil isolation and sound transmission structures are additionally arranged at the peripheries of the inner equipment, the situation that effect of the range hood becomes poor due to the pollution of oil smoke is avoided, and the situation that the response of an equipment drive is changed due to the fact that the equipment drive is affected by the oil pollution is avoided.

The invention relates to polysiloxane-imide foam and a preparation method thereof. The polysiloxane-imide foam is made by the steps: one or more than one sort of aromatic dianhydride is composed with one or more than one sort of aromatic diamine according to a certain proportion to get polyimide acid solution, then certain content of silicon-containing blocking agent, polysiloxane precursor and foam stabilizer are added sequentially, then the mixture is heated to remove small molecule volatiles so as to obtain polysiloxane precursor powder, then the powder is filled in a mould and frothed at high temperature to make soft elastic, semi-rigid and rigid polysiloxane-imide foam materials with a density of 0.01g / cm3-1.0g / cm3 and a glass transition temperature of 280 DEGC -350 DEG C. The polysiloxane-imide foam materials of the invention have good performances of high temperature resistance, low temperature resistance, flame retardancy, heat insulation and noise reduction and mechanical properties.