Nec Corporation

Ryosuke Isotani

Masanori Tsujikawa

Yoshifumi Onishi

Ken Hanazawa

Tadashi Emori

Koji Okabe

Kiyoshi Yamabana

Shuji Komeiji

Fumihiro Adachi

A noise suppression system includes an a priori S/N ratio estimated value and expectation calculation unit that acquires an expectation of a priori S/N ratio, by correcting an estimated value of the a priori S/N ratio relating to a signal and a noise based on a priori S/N ratio model or based on a signal model and a noise model, the signal and the noise being estimated from an input signal in which the signal and the noise are mixed; a noise suppression coefficient calculation unit that calculates a noise suppression coefficient with use of the expectation of the a priori S/N ratio; and a noise suppression unit that suppresses the noise included in the input signal by multiplying the input signal by the noise suppression coefficient.

Noise suppression system, noise suppression method, and recording medium storing program

A speech processing apparatus includes: an expectation value calculation unit configured to calculate, using an input signal spectrum and a speech model that models a feature quantity of speech, a spectrum expectation value which is an expectation value of a spectrum of an acoustic component included in the input signal spectrum; and an acoustic power estimation unit configured to estimate an acoustic power of the acoustic component of the input signal spectrum based on the input signal spectrum and the spectrum expectation value.

Speech processing apparatus, speech processing method, and recording medium

To remove only noise components without removing desired signal components, a signal processing apparatus includes a noise decorrelator that removes noise signals having correlation between at least two input signals, in each of which a desired signal and a noise signal coexist, by receiving the at least two input signals from at least two channels, and a residual noise remover that removes residual noise included in an output signal of the noise decorrelator based on a phase difference between the output signal of the noise decorrelator and at least one input signal included in the at least two input signals.

Signal processing apparatus, signal processing method, and signal processing program

A method for processing multichannel acoustic signals which processes input signals of a plurality of channels including the voices of a plurality of speaking persons. The method is characterized by detecting the voice section of each speaking person or each channel, detecting overlapped sections wherein the detected voice sections are common between channels, determining a channel to be subjected to crosstalk removal and the section thereof by use of at least voice sections not including the detected overlapped sections, and removing crosstalk in the sections of the channel to be subjected to the crosstalk removal.

Method for processing multichannel acoustic signal, system therefor, and program

A method for processing multichannel acoustic signals, whereby input signals of a plurality of channels including the voices of a plurality of speaking persons are processed. The method is characterized by comprising: calculating the first feature quantity of the input signals of the multichannels for each channel; calculating similarity of the first feature quantity of each channel between the channels; selecting channels having high similarity; separating signals using the input signals of the selected channels; inputting the input signals of the channels having low similarity and the signals after the signal separation; and detecting a voice section of each speaking person or each channel.

Method for processing multichannel acoustic signal, system thereof, and program

A speech recognition apparatus that performs frame synchronous beam search by using a language model score look-ahead value prevents the pruning of a correct answer hypothesis while suppressing an increase in the number of hypotheses. A language model score look-ahead value imparting deviceis provided with a word dictionarythat defines a phoneme string of a word, a language modelthat imparts a score of appearance easiness of a word, and a smoothing language model score look-ahead value calculation means. The smoothing language model score look-ahead value calculation meansobtains a language model score look-ahead value at each phoneme in the word from the phoneme string of the word defined by the word dictionaryand the language model score defined by the language modelso that the language model score look-ahead values are prevented from concentrating on the beginning of the word.

Language model score look-ahead value imparting device, language model score look-ahead value imparting method, and program storage medium

The present invention enables the recognition process at high speed even when a lot of garbage is included in the grammar. The first voice recognition processing unit generates a recognition hypothesis graph which indicates a structure of hypothesis that is derived according to a first grammar together with a score associated with respective connections of a recognition unit by executing a voice recognition process based on the first grammar to a voice feature amount of input voice, and the second voice recognition processing unit outputs the recognition result from a total score of a hypothesis which is derived according to a second grammar after executing a voice recognition process according to the second grammar that is specified to accept a section other than keywords in input voice as the garbage section to a voice feature amount of input voice, and the second voice recognition processing unit acquires the structure and the score of the garbage section from the recognition hypothesis graph.

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Tokyo, Japan

Ryosuke Isotani