Patent application number | Description | Published |
20080247569 | Noise Suppressing Apparatus and Program - A noise suppressing apparatus suppresses a noise component of a sound signal which contains the noise component and a signal component. In the apparatus, a frequency analyzing section divides the sound signal into a plurality of frames such that adjacent frames overlap with each other along a time axis, and computes a first spectrum of each frame. A noise suppressing section suppresses a noise component of the first spectrum so as to provide a second spectrum of each frame in which the noise component is suppressed. A frequency specifying section specifies a frequency of a noise component of each frame. A phase controlling section varies a phase of the noise component corresponding to the specified frequency in the second spectrum by a different variation amount each frame. A signal synthesizing section combines the frames after the second spectrum of each frame is processed by the phase controlling section, such that adjacent frames overlap with each other along the time axis so as to output the sound signal. | 10-09-2008 |
20100008520 | Noise Suppression Estimation Device and Noise Suppression Device - A noise suppression estimation device calculates a noise index value which varies according to kurtosis of a frequence distribution of magnitude of a sound signal before or after suppression of the noise component, the noise index value indicating a degree of occurrence of musical noise after suppression of the noise component in a frequency domain. For example, the noise suppression estimation device calculates first kurtosis of a frequence distribution of magnitude of the sound signal before suppression of the noise component, calculates second kurtosis of a frequence distribution of magnitude of the sound signal after suppression of the noise component, and calculates the noise index value from the first kurtosis and the second kurtosis. | 01-14-2010 |
20100125352 | Sound Processing Device - A signal processing device processes a plurality of observed signals at a plurality of frequencies. The plurality of the observed signals are produced by a plurality of sound receiving devices which receive a mixture of a plurality of sounds. In the signal processing device, a storage stores observed data of the plurality of the observed signals. The observed data represents a time series of magnitude of each frequency in each of the plurality of the observed signals. An index calculator calculates an index value from the observed data for each of the plurality of the frequencies. The index value indicates significance of learning of a separation matrix using the observed data of each frequency. The separation matrix is used for separation of the plurality of the sounds from each other at each frequency. A frequency selector selects one or more frequency according to the index value of each frequency. A learning processor determines the separation matrix by learning with a given initial separation matrix using the observed data of the selected frequency. | 05-20-2010 |
20100296665 | NOISE SUPPRESSION APPARATUS AND PROGRAM - A In a noise suppression apparatus, an extractor extracts a noise component from an audio signal. A stationary noise estimator estimates stationary noise included in the noise component. A first noise suppressor removes a spectrum of the stationary noise from a spectrum of the audio signal to an extent determined by a subtraction factor. A non-stationary noise estimator estimates a spectrum of non-stationary noise by subtracting the spectrum of the stationary noise from the spectrum of the noise component. A factor setter generates a filtering factor for emphasizing a target sound component contained in the audio signal from the spectrum of the non-stationary noise. A second noise suppressor performs a filtering process using the filtering factor on the audio signal after processing of the first noise suppressor. An index calculator calculates a kurtosis change index representing an extent of change of kurtosis in a frequence distribution of magnitude of the audio signal between the kurtosis observed when processing of the first noise suppression part is performed and the kurtosis observed when processing of the second noise suppression part is performed. A factor adjuster variably controls the subtraction factor according to the kurtosis change index. | 11-25-2010 |
20110096631 | AUDIO PROCESSING DEVICE - In an audio processing device, a target sound emphasizer generates a target sound emphasized component by emphasizing a target sound component contained in a plurality of audio signals generated by a plurality of sound receiving devices. A stereo processor generates a stereo component of a plurality of channels from the plurality of audio signals. A first adjuster adjusts a sound pressure level of the target sound emphasized component according to a first adjustment value, and a second adjuster adjusts a sound pressure level of the stereo component according to a second adjustment value. A variable setter variably sets a zoom value which is changeable between a wide angle side and a telephoto side relative to a target. An adjustment controller controls the first adjustment value according to the zoom value such that the sound pressure level of the target sound emphasized component exponentially decreases as the zoom value changes toward the wide-angle side and controls the second adjustment value according to the zoom value such that the sound pressure level of the stereo component increases as the zoom value changes toward the wide-angle side. | 04-28-2011 |
20110170707 | NOISE SUPPRESSING DEVICE - A noise suppressing device is provided for suppressing noise of a first audio signal to generate a second audio signal. In the noise suppressing device, a noise acquisition unit acquires a plurality of noise components which are different from each other. A noise suppression unit generates each suppression component by suppressing each noise component from the first audio signal, thereby providing a plurality of suppression components different from each other in correspondence to the plurality of the noise components. A signal generation unit generates the second audio signal by summing the plurality of the suppression components that are provided from the noise suppression unit. | 07-14-2011 |
20110211711 | Factor setting device and noise suppression apparatus - In a noise suppression apparatus, an index setter sets an exponent K that is a positive value. A factor setter variably sets a suppression factor according to the exponent K. A noise suppressor generates an audio signal from which a noise component is suppressed through noise suppression process of suppressing a Kth power of an amplitude of the noise component at each frequency thereof in a Kth power of an amplitude of the audio signal at each frequency thereof to a degree determined according to the suppression factor set by the factor setting part. Preferably, the index setter sets the exponent K to a value less than 0.1. | 09-01-2011 |
20120106746 | Technique for Estimating Particular Audio Component - Candidate frequencies per unit segment of an audio signal are identified. First processing section identifies an estimated train that is a time series of candidate frequencies, each selected for a different one of the segments, arranged over a plurality of the unit segments and that has a high likelihood of corresponding to a time series of fundamental frequencies of a target component. Second processing section identifies a state train of states, each indicative of one of sound-generating and non-sound-generating states of the target component in a different one of the segments, arranged over the unit segments. Frequency information which designates, as a fundamental frequency of the target component, a candidate frequency corresponding to the unit segment in the estimated train is generated for each unit segment corresponding to the sound-generating state. Frequency information indicative of no sound generation is generated for each unit segment corresponding to the non-sound-generating state. | 05-03-2012 |
20120106758 | Technique for Suppressing Particular Audio Component - A coefficient train processing section, which sequentially generates per unit segment a processing coefficient train for suppressing a target component of an audio signal, includes a basic coefficient train generation section and coefficient train processing section. The basic coefficient train generation section generates a basic coefficient train where basic coefficient values corresponding to frequencies within a particular frequency band range are each set at a suppression value that suppresses the audio signal while coefficient values corresponding to frequencies outside the particular frequency band range are each set at a pass value that maintains the audio signal. The coefficient train processing section generates the processing coefficient train, per unit segment, by changing, to the pass value, each of the coefficient values corresponding to frequencies other than the target component among the coefficient values corresponding to the frequencies within the particular frequency band range. | 05-03-2012 |
20120134508 | Audio Processing Apparatus - An audio processing apparatus generates a suppression coefficient sequence that is composed of coefficient values corresponding to frequency components of an audio signal, the frequency components being multiplied by the corresponding coefficient values to suppress noise components of the audio signal. In the audio processing apparatus, a characteristic value calculation unit calculates a noise characteristic value depending on a shape of a magnitude distribution of the audio signal. An intensity setting unit variably sets a suppression intensity of the noise components based on the noise characteristic value. A coefficient sequence generation unit generates the suppression coefficient sequence based on the audio signal and the suppression intensity. | 05-31-2012 |
20120201385 | Graphical Audio Signal Control - Signal processing section of a terminal converts acquired audio signals of a plurality of channels into frequency spectra set, calculates sound image positions corresponding to individual frequency components, and displays, on a display screen, the calculated sound image positions results by use of a coordinate system having coordinate axes of the frequency components and sound image positions. User-designated partial region of the coordinate system is set as a designated region and an amplitude-level adjusting amount is set for the designated region, so that the signal processing section adjusts amplitude levels of frequency components included in the frequency spectra and in the designated region, converts the adjusted frequency components into audio signals and outputs the converted audio signals. | 08-09-2012 |
20130129099 | SOUND PROCESSING DEVICE - In a sound processing device, an index value calculation unit calculates a first index value that follows change of a sound signal at a first following degree and a second index value that follows the change of the sound signal at a second following degree which is lower than the first following degree. An adjustment value calculation unit calculates an adjustment value effective to adjust a reverberation component of the sound signal based on difference between the first index value and the second index value. A reverberation adjustment unit applies the adjustment value to the sound signal. | 05-23-2013 |
20130243211 | SOUND PROCESSING APPARATUS - In a sound processing apparatus, a likelihood calculation unit calculates an in-region coefficient and an out-of-region coefficient indicating likelihood of generation of each frequency component of a sound signal inside and outside a target localization range, respectively, according to localization of each frequency component. A reverberation analysis unit calculates a reverberation index value according to the ratio of a reverberation component for each frequency component. A coefficient setting unit generates a process coefficient for suppressing or emphasizing a reverberation component generated inside or outside the target localization range, for each frequency component of the sound signal, on the basis of the in-region coefficient, the out-of-region coefficient and the reverberation index value. A signal processing unit applies the process coefficient of each frequency component to each frequency component of the sound signal. | 09-19-2013 |