Patents by Inventor Ryosuke Isotani

Ryosuke Isotani has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10748551
    Abstract: 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.
    Type: Grant
    Filed: July 16, 2015
    Date of Patent: August 18, 2020
    Assignee: NEC CORPORATION
    Inventors: Masanori Tsujikawa, Ryosuke Isotani
  • Patent number: 10347273
    Abstract: 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.
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: July 9, 2019
    Assignee: NEC CORPORATION
    Inventors: Shuji Komeiji, Masanori Tsujikawa, Ryosuke Isotani
  • Patent number: 10043532
    Abstract: 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.
    Type: Grant
    Filed: December 26, 2014
    Date of Patent: August 7, 2018
    Assignee: NEC CORPORATION
    Inventors: Masanori Tsujikawa, Ryosuke Isotani
  • Publication number: 20170364854
    Abstract: The purpose of the present invention is to provide a technology which is capable of appropriately evaluating a person's conduct with respect to another person. Provided is an information processing device, comprising a recognition unit 11, a detection unit 12, and an evaluation unit 13. The recognition unit 11 recognizes an evaluation subject's conduct. The detection unit 12 detects a trigger which is a state of a person other than the evaluation subject which triggers the evaluation subject's conduct. Using the detected trigger and the result of recognition by the recognition unit 13 relating to the evaluation subject's conduct, the evaluation unit 13 evaluates the evaluation subject's conduct.
    Type: Application
    Filed: December 2, 2015
    Publication date: December 21, 2017
    Inventors: Terumi UMEMATSU, Ryosuke ISOTANI, Yoshifumi OMISHI, Masanori TSUJIKAWA, Makoto TERAO, Tasuku KITADE, Shuji KOMEIJI
  • Publication number: 20170337935
    Abstract: 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.
    Type: Application
    Filed: December 8, 2015
    Publication date: November 23, 2017
    Applicant: NEC Corporation
    Inventors: Shuji KOMEIJI, Masanori TSUJIKAWA, Ryosuke ISOTANI
  • Publication number: 20170169837
    Abstract: 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.
    Type: Application
    Filed: July 16, 2015
    Publication date: June 15, 2017
    Applicant: NEC Corporation
    Inventors: Masanori Tsujikawa, Ryosuke Isotani
  • Publication number: 20170084290
    Abstract: 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.
    Type: Application
    Filed: December 26, 2014
    Publication date: March 23, 2017
    Inventors: Masanori TSUJIKAWA, Ryosuke ISOTANI
  • Patent number: 9009035
    Abstract: 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.
    Type: Grant
    Filed: February 8, 2010
    Date of Patent: April 14, 2015
    Assignee: NEC Corporation
    Inventors: Masanori Tsujikawa, Ryosuke Isotani, Tadashi Emori, Yoshifumi Onishi
  • Patent number: 8954323
    Abstract: 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.
    Type: Grant
    Filed: February 8, 2010
    Date of Patent: February 10, 2015
    Assignee: NEC Corporation
    Inventors: Masanori Tsujikawa, Tadashi Emori, Yoshifumi Onishi, Ryosuke Isotani
  • Patent number: 8682668
    Abstract: 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 device 108 is provided with a word dictionary 203 that defines a phoneme string of a word, a language model 202 that imparts a score of appearance easiness of a word, and a smoothing language model score look-ahead value calculation means 201. The smoothing language model score look-ahead value calculation means 201 obtains a language model score look-ahead value at each phoneme in the word from the phoneme string of the word defined by the word dictionary 203 and the language model score defined by the language model 202 so that the language model score look-ahead values are prevented from concentrating on the beginning of the word.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: March 25, 2014
    Assignee: NEC Corporation
    Inventors: Koji Okabe, Ryosuke Isotani, Kiyoshi Yamabana, Ken Hanazawa
  • Patent number: 8639507
    Abstract: 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.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: January 28, 2014
    Assignee: NEC Corporation
    Inventors: Fumihiro Adachi, Ryosuke Isotani, Ken Hanazawa
  • Publication number: 20120046940
    Abstract: 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.
    Type: Application
    Filed: February 8, 2010
    Publication date: February 23, 2012
    Applicant: NEC CORPORATION
    Inventors: Masanori Tsujikawa, Tadashi Emori, Yoshifumi Onishi, Ryosuke Isotani
  • Publication number: 20120029915
    Abstract: 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.
    Type: Application
    Filed: February 8, 2010
    Publication date: February 2, 2012
    Applicant: NEC CORPORATION
    Inventors: Masanori Tsujikawa, Ryosuke Isotani, Tadashi Emori, Yoshifumi Onishi
  • Publication number: 20110191100
    Abstract: 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 device 108 is provided with a word dictionary 203 that defines a phoneme string of a word, a language model 202 that imparts a score of appearance easiness of a word, and a smoothing language model score look-ahead value calculation means 201. The smoothing language model score look-ahead value calculation means 201 obtains a language model score look-ahead value at each phoneme in the word from the phoneme string of the word defined by the word dictionary 203 and the language model score defined by the language model 202 so that the language model score look-ahead values are prevented from concentrating on the beginning of the word.
    Type: Application
    Filed: March 27, 2009
    Publication date: August 4, 2011
    Applicant: Nec Corporation
    Inventors: Koji Okabe, Ryosuke Isotani, Kiyoshi Yamabana, Ken Hanazawa
  • Publication number: 20110131043
    Abstract: 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.
    Type: Application
    Filed: December 22, 2008
    Publication date: June 2, 2011
    Inventors: Fumihiro Adachi, Ryosuke Isotani, Ken Hanazawa