Patents by Inventor Takashi Hiekata

Takashi Hiekata 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).

  • Publication number: 20080267423
    Abstract: An object sound extraction apparatus includes sound source separation sections for separating and generating an object sound separation signal corresponding to an object sound and reference sound separation signals corresponding to the other reference sound based on each combination of a main acoustic signal and sub acoustic signals, an object sound separation signal synthesis section for synthesizing the object sound separation signals, and a spectrum subtraction processing section for extracting an acoustic signal corresponding to the object sound from the synthesis signal by performing a spectrum subtraction processing between the synthesis signal and the reference sound separation signals. Accordingly, in acoustic environments where the object sound and the noises are mixed in the acoustic signals obtained via the microphones, and the mixed conditions can vary, a high object sound extraction performance can be ensured by a small object sound extraction apparatus.
    Type: Application
    Filed: April 7, 2008
    Publication date: October 30, 2008
    Inventors: Takashi Hiekata, Takashi Morita, Yohei Ikeda, Toshiaki Shimoda
  • Publication number: 20080027714
    Abstract: To shorten an output delay while a high sound source separation performance is ensured when a sound separation process based on an ICA method is performed. A second Fourier transform process execution cycle t2 for obtaining a second frequency-domain signal S1 used as an input signal of a filter process is set shorter than a first Fourier transform process execution cycle t1 for obtaining a first frequency-domain signal used for a learning computation of a separating matrix. When the time length of a second time-domain signal S1 is set shorter than a time length of a first time-domain signal S0, a second separating matrix used for a filter process is set by aggregating matrix components of a first separating matrix obtained through a learning calculation for every a plurality of groups.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 31, 2008
    Inventors: Takashi Hiekata, Yohei Ikeda
  • Publication number: 20070133811
    Abstract: A sound source separation apparatus performs a temporary learning processing and a temporary separation processing with respect to each of a plurality of candidate matrixes (separating matrixes obtained by learning calculation based on input signals of different sound source conditions) stored on a candidate matrix memory in advance. The apparatus determines an initial matrix of the separating matrix based on the obtained correlation evaluation of the separated signals. The learning calculations of the initial matrix determination processing and separating matrix based on the initial matrix are performed at a time of the sound source separation processing by the apparatus and when a degree of correlation among the separated signals by a correlation evaluation part exceeds a predetermined level.
    Type: Application
    Filed: November 22, 2006
    Publication date: June 14, 2007
    Inventors: Hiroshi Hashimoto, Takashi Hiekata, Takashi Morita, Yohei Ikeda
  • Publication number: 20070025556
    Abstract: A sound source separation apparatus includes a first sound source separation unit that performs blind source separation based on independent component analysis to separate a sound source signal from a plurality of mixed sound signals, thereby generating a first separated signal; a second sound source separation unit that performs real-time sound source separation by using a method other than the blind source separation based on independent component analysis to generate a second separated signal; and a multiplexer that selects one of the first separated signal and the second separated signal as an output signal. The first sound source separation unit continues processing regardless of the selection state of the multiplexer. When the first separated signal is selected as an output signal, the number of sequential calculations of a separating matrix performed in the first sound source separation unit is limited to a number that allows for real-time processing.
    Type: Application
    Filed: July 20, 2006
    Publication date: February 1, 2007
    Inventor: Takashi Hiekata
  • Publication number: 20070025564
    Abstract: A sound source separation apparatus performs a discrete Fourier transform on each of a plurality of mixed sound signals for a predetermined time length in a time domain and sequentially transforms the mixed sound signals to mixed sound signals in a frequency domain. The apparatus allocates learning calculations of a separating matrix using a blind source separation based on independent component analysis to a plurality of DSPs for each of separate mixed sound signals generated by separating the frequency-domain-based mixed sound signal into a plurality of pieces with respect to frequency range and causes the DSPs to perform the learning calculations in parallel so as to sequentially output the separating matrix. The apparatus generates a separated signal corresponding to the sound source signal from the frequency-domain-based mixed sound signal by performing a matrix calculation using the separating matrix and performs an inverse discrete Fourier transform on the separated signal.
    Type: Application
    Filed: July 21, 2006
    Publication date: February 1, 2007
    Inventors: Takashi Hiekata, Hiroshi Hashimoto