| 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 |
