90 results about "Noise masking" patented technology

The invention provides a method and apparatus for noise reduction of a signal, for example speech enhancement of a speech signal. The method involves a two-stage algorithm comprising performing a preprocessing first spectral subtraction to remove tonal noise and generate a tonal noise removed signal, and performing a second spectral subtraction to remove noise from the said tonal noise removed signal. In both spectral subtraction stages noise is not removed completely but only to a level below an audible threshold in order to avoid unwanted artifacts.

A method for providing a reduced exposure value for radiographic imaging obtains a set of flat-field images at two or more exposure values and measures the noise power spectra using the flat field images. At least one noise table is generated according to interpolated noise power spectra for a set of predetermined exposure values. Values from the at least one noise table are applied to a clinical image to form a reduced exposure simulation image. A noise mask is generated according to at least one noise table and the exposure values of the reduced exposure simulation image and added to the reduced exposure simulation image. The reduced exposure simulation image is assessed to generate a desired dose reduction factor.

A method is provided that includes acquiring a first set of image data from X-rays produced at a first energy level and a second set of image data from X-rays produced at a second energy level. The method includes generating a first noise mask for a first basis material and a second noise mask for a second basis material and removing pixels corresponding to cross contaminating structural information from the first noise mask and the second noise mask. The method includes processing a first materially decomposed image generated from the first set of image data and the second set of digital data using the second noise mask after removal of the cross contaminating structural information and processing a second MD image generated from the first set of image data and the second set of digital data using the first noise mask after removal of the cross contaminating structural information.

A method for inspecting a component is provided. The method includes generating an image of the component, generating a signal indication mask, and generating a noise mask using a signal within the signal indication mask. The noise mask facilitates reducing a quantity of prospective signals contained in the signal indication mask. The method further includes utilizing the signal indication mask and the generated noise mask to calculate the signal-to-noise ratio of at least one potential flaw indication that may be present in the image.

The invention provides a method and device for detecting a voice endpoint. The method comprises the steps of determining and recording energies of frames of a signal to be detected, tracking the minimum energy based on the energies of the frames, masking noise for the signal to be detected and the tracked minimum energy through the noise masking energy, determining the signal-to-noise ratio of the frames through the signal to be detected and the tracked minimum energy obtained after noise masking, judging voice according to the signal-to-noise ratio of the frames and a preset threshold value, and then determining the voice endpoint. The situation of singular values caused when the partial minimum energy tends to be zero is avoided through the noise masking mode, the false alarm rate is reduced, meanwhile, the dynamic range of the signal-to-noise ratio of a sub-band is narrowed, and the robustness of a detection result is improved.

Methods and apparatuses for addressing open space noise are disclosed using both dynamic and static sound masking. In one example, an adaptive sound masking system and method portions undesired sound into time-blocks and estimates frequency spectrum and power level, and continuously generates masking noise with a matching or predetermined spectrum and loudness or power level to mask the undesired sound. In another example, a static sound masking system and method portions undesired sound into time-blocks and estimates frequency spectrum and power level, and generates a static noise-masking signal with a matching spectrum and power level to mask the undesired sound.

Disclosed is a microphone-array-based speech recognition system and method. The speech recognition system combines a noise cancelling technique for cancelling noise of input speech signals from an array of microphones, according to at least an inputted threshold. The system receives noise-cancelled speech signals outputted by a noise masking module through at least a speech model and at least a filler model, then computes a confidence measure score with the at least a speech model and the at least a filler model for each threshold and each noise-cancelled speech signal, and adjusts the threshold to continue the noise cancelling for achieving a maximum confidence measure score, thereby outputting a speech recognition result related to the maximum confidence measure score.

A signal separation system and a method for automatically selecting a threshold to separate sound sources. The signal separation system calculates a power sequence for a target signal using a target mask, and a power sequence for an interference signal using a complementary mask, based on signals received from a plurality of microphones; applies a nonlinearity to the target signal power sequence and the interference signal power sequence; calculates a correlation coefficient of the nonlinear target signal power sequence and the nonlinear interference signal power sequence; and sets a noise masking threshold that minimizes the correlation coefficient.

The present invention relates to a voice frequency coding method containing two portions of coding voice signal and quantization, and includes the following steps: dividing time domain voice frequency signal, into the framke with a certain length; making time domain signal of every frame undergo the process of time frequency conversion to obtain frequency domain coefficient, dividing the frequency domain coefficient of every frame into different frequency subbands, at the same time, making the time domain signal undergo the process of psychological acoustic model analysis to obtain noise masking threshold of every frequency domain subband, under the control of the noise masking threshold of every subband distributing making bit distribution and quantization of frequency domain coefficient of every subband, and making entropy coding so as to effectively raise compression efficiency.

The present invention provides a method for masking noise in a motor vehicle that has a component that produces noise when operated. The method of the invention comprises monitoring the speed of the vehicle, and increasing the movement of the moveable part when the vehicle is at a predetermined speed. It is well known that vehicles naturally produce more noise as the speed of the vehicle is increased. The invention also provides a noise masking system that exploits the method of the invention.

A method and system for displaying fractional bit data in order to increase the bit depth of a PWM display without requiring the use of an excessive number of bit planes. One embodiment of the present invention combines the outputs of two random number generators (702) with the outputs of a row counter (704) and column counter (706) to yield row and column indexes into two 32×32 cell blue noise masks. The row and column indexes select a blue noise mask threshold for a given pixel. The threshold from the first blue noise mask (708) is applied to a comparator (710) where it is compared to the fractional bit portion of the pixel data. A first blue noise bit, BN(1), is generated based on this comparison. Typically, BN(1) is a “1” when the fractional portion of the pixel data exceeds the threshold value from the mask. The same threshold data is also processed by inverter (712) to produce the threshold that would be shored in an inverted form of Mask A. Inverter (712) prevents the circuitry from having to store four separate blue noise masks. The output of the inverter (712) is also compared to the fractional pixel data to produce a second blue noise bit, BN(2). In the same manner, the second blue noise mask (714) is used to generate two additional blue noise bits. The four blue noise bits are then used alternately in the quad-frame display of FIG. 5 with the integer portion of the pixel data.

Disclosed is an apparatus for generating a ranging pseudo noise (PN) code used in a base station of a portable internet system of an orthogonal frequency division multiplexing access scheme, wherein a ranging pseudo noise mask value is generated using a cell ID number, and then the generated ranging pseudo noise mask value is stored in a memory. A final ranging PN code is generated using the stored ranging PN mask value and a status of a pseudo random binary sequence for generating a ranging PN code. With such a structure, the maximal 256-numbered ranging PN code values can be obtained simultaneously with each 144 bit-length.

The invention discloses a wind turbine generator noise masking device based on the noise control technique. The wind turbine generator noise masking device comprises a pre-collection unit, a storage unit, a signal collection unit, a processing unit and a sound playing unit. The invention further discloses a wind turbine generator noise masking method based on the noise control technique. The wind turbine generator noise masking method based on the noise control technique comprises the following steps that the pre-collection unit collects natural wind sound samples and wind turbine generator noise samples in resident residences and manufactures narrow-band sound samples with different sound pressure levels and different frequency bands, and the narrow-band sound samples are stored into the storage unit; the signal collection unit records the parameters of wind speed, air humidity, blade positions and the like during operation of the wind turbine generator, and therefore the noise spectrum data of the wind turbine generator are obtained; the processing unit enables the noise spectrum of the wind turbine generator to be compared with natural wind sound spectrum, and the frequency spectrum of sound samples which need to be superposed is calculated; sound samples which need to be superposed are composed by the processing unit with the utilization of the narrow-band sound samples according to the frequency spectrum of the sound samples which need to be superposed, the sound samples which need to be superposed are played through the sound playing unit, and therefore the noise, heard in the resident residences, of the wind turbine generator is made to be similar to wind sound.

The invention discloses a novel waveform parameter-audio-fused ultra-wideband radar life detector. A radar echo is divided into two paths: one path is processed and extracted into a respiratory signal, and then whether the respiratory signal is a life parameter of a human being is intelligently identified; and the other path is processed into an audio signal through amplitude modulation or frequency modulation, and through multi-channel and noise masking characteristics of a human ear, information carried by the radar echo is monitored in real time in a listening way to obtain information which is difficultly expressed by waveform of an ultra-wideband biological radar echo so as to identify whether a biological radar echo signal carries life information artificially. Through the two processing and identifying ways, the life detection accuracy is greatly improved; and the novel waveform parameter-audio-fused ultra-wideband radar life detector breaks through a limitation that the conventional radar life detector relies on a single waveform parameter for identification, improves the practicality of the radar life detector and has a good application prospect.

A sound machine having a pseudo random white noise generator provides white noise sound therapy of selectable tone/texture, bandwidth and/or peak frequency to those suffering from tinnitus or others seeking noise-masking or sleep or relaxation. The sound machine having a pseudo random white noise generator includes a user input interface having a tone/texture user input control, a band pass user input control and a peak select user input control. The tone/texture user input control selects the tone/texture of the white noise sound generated, the bandpass user input control the bandpass of the white noise sound generated and the peak select user input control provides the ability to select frequency peaks of the white noise sound generated.