Patent application number | Description | Published |
20080208577 | Multi-stage speech recognition apparatus and method - Provided are a multi-stage speech recognition apparatus and method. The multi-stage speech recognition apparatus includes a first speech recognition unit performing initial speech recognition on a feature vector, which is extracted from an input speech signal, and generating a plurality of candidate words; and a second speech recognition unit rescoring the candidate words, which are provided by the first speech recognition unit, using a temporal posterior feature vector extracted from the speech signal. | 08-28-2008 |
20090060222 | Sound zoom method, medium, and apparatus - A sound zoom method, medium, and apparatus generating a signal in which a target sound is removed from sound signals input to a microphone-array by adjusting a null width that restricts a directivity sensitivity of the microphone array, and extracting a signal corresponding to the target sound from the sound signals by using the generated signal. Thus, a sound located at a predetermined position away from the microphone array can be selectively obtained so that a target sound is efficiently obtained. | 03-05-2009 |
20090086998 | Method and apparatus for identifying sound sources from mixed sound signal - A method and apparatus for discriminating sound sources from a mixed sound is provided. The method includes separating sound source signals from a mixed sound signal including a plurality of sound source signals that are input through a microphone array, estimating a transfer function of a mixing channel mixing the plurality of sound source signals from relationships between the mixed sound signal and the separated sound source signals, obtaining input signals of the microphone array by multiplying the estimated transfer function by the separated sound source signals, and calculating location information of each sound source using a predetermined sound source location estimation method based on the obtained input signals. | 04-02-2009 |
20090097360 | Method and apparatus for measuring sound source distance using microphone array - A method and apparatus for measuring a distance to a sound source. The method includes combining sound source signals input through at least two microphones and generating at least two microphone output signals, and performing an operation on the generated microphone output signals and calculating a distance to a sound source by using the relationship between a result of the operation and a frequency of the input sound source signals. Accordingly, regardless of the strength of a sound source, the distance to a sound source can be measured. | 04-16-2009 |
20090097670 | Method, medium, and apparatus for extracting target sound from mixed sound - A method, medium, and apparatus for extracting a target sound from mixed sound. The method includes receiving a mixed signal through a microphone array, generating a first signal whose directivity is emphasized toward a target sound source and a second signal whose directivity toward the target sound source is suppressed based on the mixed signal, and extracting a target sound signal from the first signal by masking an interference sound signal, which is contained in the first signal, based on a ratio of the first signal to the second signal. Therefore, a target sound signal can be clearly separated from a mixed sound signal which contains a plurality of sound signals and is input to a microphone array. | 04-16-2009 |
20090129609 | Method and apparatus for acquiring multi-channel sound by using microphone array - Provided are a method and an apparatus for acquiring a multi-channel sound by using a microphone array. The method estimates positions of sound sources corresponding to sound source signals, which are mixed together, from the sound source signals input via a microphone array; and generates a multi-channel sound source signal by compensating for the sound source signals, based on differences between the estimated positions of the sound sources and a position of a virtual microphone array substituting for the microphone array. By doing so, the multi-channel sound having a stereoscopic effect can be acquired from a plurality of distant sound source signals which are input via the microphone array from a portable sound acquisition device. | 05-21-2009 |
20090129610 | Method and apparatus for canceling noise from mixed sound - A method, medium, and apparatus canceling noise from a mixed sound. The method includes receiving sound source signals including a target sound and noise, extracting at least one feature vector indicating an attribute difference between the sound source signals from the sound source signals, calculating a suppression coefficient considering ratios of noise to the sound source signals based on the at least one extracted feature vector, and canceling the sound source signals corresponding to noise by controlling an intensity of an output signal generated from the sound source signals according to the calculated suppression coefficient. Accordingly, a clear target sound source signal can be obtained. | 05-21-2009 |
20090141908 | Distance based sound source signal filtering method and apparatus - Provided is a sound source signal filtering method and apparatus. The sound source signal filtering method includes: generating two or more microphone output signals by combining sound source signals input through a plurality of microphones; calculating distances between the microphones and a sound source from which the sound source signals are emitted by using distance relationships according to frequencies of the sound source signals extracted from the generated microphone output signals; and filtering the sound source signals to obtain one or more sound source signals corresponding to a predetermined distance by using the calculated distances. Accordingly, it is possible to obtain only sound source signals emitted from a sound source at a particular distance from the microphone array among a plurality of sound source signals input through the microphone array. | 06-04-2009 |
20090232330 | Apparatus and method for automatic gain control using phase information - An apparatus and a method for automatically controlling a gain using phase information are provided. The apparatus includes a frequency conversion unit converting each of input signals received from a plurality of acoustic input apparatuses to frequency input signals, a factor determination unit determining a scaling factor according to a gain difference between the input signals based on a phase difference of the frequency input signals, and a scaling performance unit performing scaling for gain compensation between the input signals based on the scaling factor. | 09-17-2009 |
20090279715 | Method, medium, and apparatus for extracting target sound from mixed sound - A method, medium, and apparatus for extracting a target sound from a mixed sound. The method includes obtaining the mixed signal from a microphone array, generating a first signal which is emphasized and directed toward a target sound source, and a second signal which is suppressed and directed toward the target sound source, calculating a non-linear filter which is adaptive to at least one of an amplitude ratio of the first signal to the second signal in a time-frequency domain, frequencies of the first and second signals, and a ratio of an interference signal to the mixed signal, and filtering the first signal by the non-linear filter. | 11-12-2009 |
20100092000 | APPARATUS AND METHOD FOR NOISE ESTIMATION, AND NOISE REDUCTION APPARATUS EMPLOYING THE SAME - Provided are an apparatus and method for estimating noise and a noise reduction apparatus employing the same. The noise estimation apparatus estimates noise by blocking audio signals from a direction of a target sound source from received audio signals, and compensating for distortions from directivity gains of a target sound blocker blocking the audio signals from the target sound source. | 04-15-2010 |
20100110834 | APPARATUS AND METHOD OF DETECTING TARGET SOUND - An apparatus and method of voice activity detection (VAD) are disclosed. To detect a target sound, a target sound detecting apparatus calculates the phase difference corresponding to each frequency component from a plurality of sound signals converted in frequency domain, calculates a characteristic value indicating possibility that the phase difference of the frequency component is within an allowable phase difference range of target sound calculated based on a direction angle of the target sound, and detects the presence and/or absence of target sound using the characteristic value. | 05-06-2010 |
20100114570 | APPARATUS AND METHOD FOR RESTORING VOICE - An apparatus and a method for restoring voice are provided. The apparatus reduces noise included in a voice signal input to a microphone and outputs a voice signal having reduced noise, detects harmonic frequencies from the voice signal having reduced noise, and restores the voice signal having reduced noise approximate to its original state before being input to the microphone according to detected harmonic frequencies of the voice signal having reduced noise. | 05-06-2010 |
20100118201 | SOUND ZOOMING APPARATUS AND METHOD SYNCHRONIZED WITH MOVING PICTURE ZOOMING FUNCTION - A sound zooming technique synchronized with a moving picture zooming function is disclosed. A signal to control ambient noise and a signal to control a long distance sound are extracted from an audio signal input through a plurality of microphones. A front directivity-emphasized signal is masked using the two signals and a weighted value to control volume. | 05-13-2010 |
20100119079 | APPRATUS AND METHOD FOR PREVENTING NOISE - Provided are an apparatus and method for preventing noise. The apparatus estimates a noise signal from a signal transformed into a frequency domain, uses the estimated noise signal to estimate the amplitude of the frequency-domain signal according to a frequency band, and then calculates a phase difference according to a frequency band and eliminates or prevents noise from the amplitude-estimated frequency-domain signal based on the calculated phase difference according frequency band. | 05-13-2010 |
20100254539 | APPARATUS AND METHOD FOR EXTRACTING TARGET SOUND FROM MIXED SOURCE SOUND - A technology for eliminating or reducing interference sound from a sound signal to extract target sound is provided. Interference sound is modeled using training noise, and mixed source sound is separated using the modeled interference sound. The mixed source sound is separated into target sound and interference sound using a basis matrix of the modeled interference sound. | 10-07-2010 |
20110051956 | APPARATUS AND METHOD FOR REDUCING NOISE USING COMPLEX SPECTRUM - An apparatus and method reduce noise in a complex spectrum domain to extract a target signal from input signals containing noise and target speech. Noise estimation may be performed through a filter with a filter learning coefficient that is updated according to a prior-signal-to-noise ratio (prior-SNR). Also, noise estimation accuracy may be improved by using confidential weighted scores. The target signal may be extracted by representing candidates of the target signal as at least two circles in the complex spectrum domain using the estimated noise and then geometrically calculating the intersections of the circles. | 03-03-2011 |
20110075859 | APPARATUS FOR GAIN CALIBRATION OF A MICROPHONE ARRAY AND METHOD THEREOF - An apparatus and method for calibrating gain difference between microphones included in a microphone array are provided. In the gain calibrating apparatus, weights for each frequency component of the acoustic signals, which have been converted into the signals in the frequency domain are calculated. The weights are used to calibrate the acoustic signals such that the plurality of acoustic signals each have the same amplitude while the acoustic signals maintain their individual phase. The amplitudes of the acoustic signals are calibrated by use of the calculated weights. The gain calibrating apparatus calibrates gain in real time while calculating weights for frequency components of the frame of acoustic signals in real time. | 03-31-2011 |
20110235822 | APPARATUS AND METHOD FOR REDUCING REAR NOISE - An apparatus and method for removing noise are provided. The apparatus includes an acoustic signal input unit configured to comprise three or more microphones including a first microphone as a reference microphone, a second microphone disposed at a position asymmetrical to the first microphone, and a third microphone disposed at a position symmetrical to the first microphone, and an acoustic signal processing unit configured to remove rear noise using acoustic signals received from the first microphone, the second microphone, and the third microphone. | 09-29-2011 |
20120169826 | MICROPHONE ARRAY APPARATUS HAVING HIDDEN MICROPHONE PLACEMENT AND ACOUSTIC SIGNAL PROCESSING APPARATUS INCLUDING THE SAME - A microphone array apparatus is provided. The microphone array apparatus includes a plurality of first type microphones which are disposed to be hidden in a direction of a target source and surrounded by a cover that passes acoustic signals therethrough, and a plurality of second type microphones which are disposed at both sides of the plurality of first type microphones. | 07-05-2012 |
20120179458 | APPARATUS AND METHOD FOR ESTIMATING NOISE BY NOISE REGION DISCRIMINATION - Provided are an apparatus and method for estimating noise that changes with time. The apparatus may calculate a speech absence probability that indicates the possibility of the absence of speech in each frequency component of an input acoustic signal, may discriminate between a speech-dominant region and a noise region from the acoustic signals based on the speech absence probability, and may estimate noise according to the discrimination result. | 07-12-2012 |
20130022217 | SOUND ZOOM METHOD, MEDIUM, AND APPARATUS - A sound zoom method, medium, and apparatus generating a signal in which a target sound is removed from sound signals input to a microphone array by adjusting a null width that restricts a directivity sensitivity of the microphone array, and extracting a signal corresponding to the target sound from the sound signals by using the generated signal. Thus, a sound located at a predetermined position away from the microphone array can be selectively obtained so that a target sound is efficiently obtained. | 01-24-2013 |
20130129113 | SOUND SOURCE SIGNAL FILTERING APPARATUS BASED ON CALCULATED DISTANCE BETWEEN MICROPHONE AND SOUND SOURCE - Provided is a sound source signal filtering method and apparatus. The sound source signal filtering method includes: generating two or more microphone output signals by combining sound source signals input through a plurality of microphones; calculating distances between the microphones and a sound source from which the sound source signals are emitted by using distance relationships according to frequencies of the sound source signals extracted from the generated microphone output signals; and filtering the sound source signals to obtain one or more sound source signals corresponding to a predetermined distance by using the calculated distances. Accordingly, it is possible to obtain only sound source signals emitted from a sound source at a particular distance from the microphone array among a plurality of sound source signals input through the microphone array. | 05-23-2013 |
20140056106 | SOUND SOURCE SIGNAL FILTERING APPARATUS BASED ON CALCULATED DISTANCE BETWEEN MICROPHONE AND SOUND SOURCE - Provided is a sound source signal filtering method and apparatus. The sound source signal filtering method includes: generating two or more microphone output signals by combining sound source signals input through a plurality of microphones; calculating distances between the microphones and a sound source from which the sound source signals are emitted by using distance relationships according to frequencies of the sound source signals extracted from the generated microphone output signals; and filtering the sound source signals to obtain one or more sound source signals corresponding to a predetermined distance by using the calculated distances. Accordingly, it is possible to obtain only sound source signals emitted from a sound source at a particular distance from the microphone array among a plurality of sound source signals input through the microphone array. | 02-27-2014 |