Fujitsu Corporation

Semiconductor Energy Laboratory Co., Ltd.

Chikako Matsumoto

Naoshi Matsuo

Mitsuaki Fukuda

Takushi Fujita

Hitoshi Matsumoto

Masaaki Oota

Shuro Shindo

Yuichi Nagai

Waku Ooe

Kiyoshi Kato

Yasuji Ota

Kaori Endo

Taro Togawa

Yasuyuki Takahashi

Nobuyuki Washio

Yasuo Sato

Shinta Kimura

Eiichiro Yamamoto

A non-transitory computer-readable storage medium storing a program that causes a computer to execute a process, the process includes setting a plurality of speaker regions in different directions; calculating a phase difference in each of a plurality of different frequency bands on the basis of a plurality of sound signals acquired by the plurality of microphones; calculating a representative value of the number of phase differences belonging to each of a plurality of phase difference regions corresponding to each of the plurality of speaker regions on the basis of the calculated phase differences and the set plurality of speaker regions; comparing magnitudes of the calculated representative values; and determining, as a direction in which a speaker exists, a direction of a speaker region corresponding to a phase difference region where the compared representative value is large.

Storage medium, speaker direction determination method, and speaker direction determination device

A speech recognition method to be performed by a computer, the method including: detecting a first keyword uttered by a user from an audio signal representing voice of the user; detecting a term indicating a request of the user from sections that follow the first keyword in the audio signal; and determining a type of speech recognition processing applied to the following sections in accordance with the detected term indicating the request of the user.

Determining a type of speech recognition processing according to a request from a user

A method for determining an utterance direction includes: executing a first calculation process that includes determining an utterance direction region based on a phase difference of each given frequency between a first frequency signal and a second frequency signal inputted to a first and second voice input section respectively, and performing a process of calculating a first phase difference deviation degree indicating the degree by which the phase difference of each given frequency is deviated from the utterance direction region; executing a second calculation process for calculating a second phase difference deviation degree from the first phase difference deviation degree of the plurality of frames; and executing an utterance direction determination process for determining that a user is uttering a voice to the first voice input section and the second voice input section when the second phase difference deviation degree is equal to or smaller than a first threshold value.

Method for utterance direction determination, apparatus for utterance direction determination, non-transitory computer-readable storage medium for storing program

A voice signal processing method includes: converting a first and a second voice signals to a first and a second frequency signals; setting a coefficient of existence representing degree of existence of a target sound and a coefficient of non-existence representing degree of existence of a non-target sound based on a phase difference for each of the predetermined frequencies between the first and the second frequency signals and a target sound existence region indicating an existence position of the target sound; and judging whether the first voice and/or the second voice include the target sound, based on the coefficient of existence, the coefficient of non-existence and a representative value corresponding to either one of the first and the second frequency signals.

Medium for voice signal processing program, voice signal processing method, and voice signal processing device

A method includes: acquiring a delay amount of a second transfer function relative to a first transfer function, the first and second transfer function indicating sound transfer characteristics in a head of a user for a first and second sound source direction; and calculating a value of a third transfer function regarding a third sound source direction at the elapsed time, by interpolating a first value and a second value based on a first angular difference and a second angular difference, the first value being a value of the first transfer function at the elapsed time, the second value being a value of the second transfer function at a time after the elapsed time, the first angular difference being between the third sound source direction and the first sound source direction, the second angular difference being between the third sound source direction and the second sound source direction.

Audio processing method, audio processing apparatus, and non-transitory computer-readable storage medium for storing audio processing computer program

A noise suppressing apparatus calculates a phase difference on the basis of a first and second sound signal obtained by a microphone array; calculates a first sound arrival rate on the basis of a first phase difference area and the phase difference and a second sound arrival rate on the basis of a second phase difference area and the phase difference; calculates a dissimilarity that represents a level of difference between the first sound arrival rate and the second sound arrival rate; determines whether the pickup target sound is included in the first sound signal on the basis of the dissimilarity; and determines a suppression coefficient to be applied to the frequency spectrum of the first sound signal, on the basis of a result of the determination of whether the pickup target sound is included and on the basis of the phase difference.

Noise suppressing apparatus, speech recognition apparatus, and noise suppressing method

A voice processing apparatus calculates a phase difference between first and second frequency signals obtained by transforming first and second voice signals generated by two voice input units for each frequency, calculates, for each extension range set outside or inside a reference range, a presence ratio based on the number of frequencies with the phase difference between the first and second frequency signals falling within the extension range, the reference range representing a range of the phase difference between the first and second voice signals for each frequency and corresponding to a direction in which a target sound source is assumed to be located, and sets, as a non-suppression range, a first extension range having the presence ratio higher than a predetermined value and a second extension range closer to the phase difference at the center of the reference range than the first extension range is within the reference range.

Voice processing apparatus and voice processing method

A voice processing device includes a noise-originating coefficient calculation section that calculates a noise-originating coefficient that gradually decreases as a target value of stationary noise for each frequency increases, the target value being calculated based on an amplitude value of a frequency spectrum obtained by time-frequency transforming a voice signal for a predetermined period of time, and a suppression signal generation section that generates, when the frequency spectrum is determined as being stationary on the basis of the amplitude value, a suppression signal by multiplying a suppression coefficient based on the noise-originating coefficient by the amplitude value, the suppression signal being frequency-time transformed to be output.

Voice processing device, noise suppression method, and computer-readable recording medium storing voice processing program

A noise suppression device includes a memory, and a processor coupled to the memory and configured to generate a first input signal and a second input signal by converting a first sound signal and a second sound signal from time domain to frequency domain, the first sound signal and the second sound signal being collected by a first microphone and a second microphone, respectively, based on the first input signal and the second input signal, determine a stationary noise model, calculate a signal to noise ratio (SNR) based on the first input signal and the stationary noise model, based on the SNR ratio, set a range of phase difference to suppress the first input signal, calculate a phase difference between the first input signal and the second input signal, and when the phase difference is within the range of phase difference, suppress the first input signal.

Noise suppression device and method of noise suppression

A noise suppression device includes a generator to generate, on basis of phase differences between phases of the signals input from microphones, additional data obtained by rotating the phase differences; an estimator to select one or multiple ranges in association with a direction in which a sound source of a target sound included in the input signals exists at a high probability, and to estimate, on basis of the phase differences and the additional data, a range that is among the selected one or multiple ranges and in which the sound source exists; and an output signal generator configured to generate, on basis of a suppression coefficient set on basis of a result of determination of whether or not the sound source exists in the estimated range, a output signal in which the noise in the input signals is suppressed.

Noise suppression device, noise suppression method, and non-transitory computer-readable recording medium storing program for noise suppression

A noise suppression device includes a phase difference derived suppression coefficient computation section that over a phase difference utilization range computes for each frequency a phase difference derived suppression coefficient based on a phase difference, an amplitude ratio derived suppression coefficient computation section that computes for each frequency an amplitude ratio derived suppression coefficient based on an amplitude ratio or an amplitude difference, and based on the amplitude conditions, and a suppression section that suppresses noise contained in the input sound signals based on a suppression coefficient determined by using the phase difference derived suppression coefficient and the amplitude ratio derived suppression coefficient.

Noise suppression device and method

A microphone sensitivity difference correction device includes a detection section that detects a frequency domain signal expressing a stationary noise, based on frequency domain signals of input sound signals respectively input from plural microphones; a first correction section that employs the stationary noise to compute a first correction coefficient for correcting the sensitivity difference between the plural microphones by a frame unit; and a second correction section that employs the frequency domain signals that have been corrected by the first correction section to compute a second correction coefficient for correcting by frequency unit the sensitivity difference between the plural microphones for each of the frames.

Microphone sensitivity difference correction device, method, and noise suppression device

A noise suppression apparatus includes: a conversion unit to convert a recorded sound signal in a time domain into a spectrum in a frequency domain; a setting unit to set a suppression gain indicating a degree of suppression on each spectrum for each frequency spectrum on the basis of a nonstationarity-value variation in time of the respective spectrum; a suppression unit to suppress each of the spectrum on the basis of the suppression gain set by the setting unit for each frequency spectrum; and an inverse conversion unit to perform an inverse conversion to the conversion by the conversion unit on the spectrum having been subjected to the suppression processing by the suppression unit.

Noise suppression apparatus, method, and a storage medium storing a noise suppression program

A computer implemented method comprising: setting a plurality of frames on a time axis between a first waveform of an input to audio processing and a second waveform of an output from the audio processing, detecting a voice frame and a noise frame in the first and second waveform, calculating a first and second spectrum from the first and second waveform, adjusting level of the first or second spectrum of the noise frame, setting the adjusted first and second spectrum of the noise frame as a third and fourth spectrum, calculating a distortion amount of the noise frame from the third and fourth spectrum, estimating a noise model spectrum from the first or second spectrum, determining a selected frequency by comparison of voice and noise frame spectrum levels, and calculating a distortion amount of the voice frame from the first and second spectrum of the voice frame at the selected frequency.

Computer-readable medium for recording audio signal processing estimating a selected frequency by comparison of voice and noise frame levels

A voice processing apparatus includes: a phase difference calculation unit which calculates for each frequency band a phase difference between first and second frequency signals obtained by applying a time-frequency transform to sounds captured by two voice input units; a detection unit which detects a frequency band for which the percentage of the phase difference falling within a first range that the phase difference can take for a specific sound source direction, the percentage being taken over a predetermined number of frames, does not satisfy a condition corresponding to a sound coming from the direction; a range setting unit which sets, for the detected frequency band, a second range by expanding the first range; and a signal correction unit which makes the amplitude of the first and second frequency signals larger when the phase difference falls within the second range than when the phase difference falls outside the second range.

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Yokohama, Japan

Chikako Matsumoto