Acoustic signal processing apparatus, acoustic signal processing method and computer readable medium
First Claim
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1. An acoustic signal processing apparatus comprising:
- an acoustic signal inputting unit configured to input a plurality of acoustic signals obtained by a plurality of microphones arranged at different positions;
a frequency decomposing unit configured to respectively decompose each acoustic signal into a plurality of frequency components, and for each frequency component, generate frequency decomposition information for which a signal level and a phase have been associated;
a phase difference computing unit configured to compute a phase difference between two predetermined pieces of the frequency decomposition information, for each corresponding frequency component;
a two-dimensional data converting unit configured to convert into two dimensional data made up of point groups arranged on a two-dimensional coordinate system having a frequency component function as a first axis and a phase difference function as a second axis;
a voting unit configured to perform Hough transform on the point groups, generate a plurality of loci respectively corresponding to each of the point groups in a Hough voting space, and when adding a voting value to a position in the Hough voting space through which the plurality of loci passes, perform addition by varying the voting value based on a level difference between first and second signal levels respectively indicated by the two pieces of frequency decomposition information; and
a shape detecting unit configured to retrieve a position where the voting value becomes maximum to detect, from the two-dimensional data, a shape which corresponds to the retrieved position, which indicates a proportional relationship between the frequency component and the phase difference, and which is used to estimate a sound source direction of each of the acoustic signals.
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Abstract
Hough transform is performed on the point groups forming two dimensional data to generate a plurality of loci respectively corresponding to each of the point groups in a Hough voting space. When adding a voting value to a position in the Hough voting space through which the plurality of loci passes, addition is performed by varying the voting value based on a level difference between first and second signals respectively indicated by the two pieces of frequency decomposition information.
35 Citations
12 Claims
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1. An acoustic signal processing apparatus comprising:
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an acoustic signal inputting unit configured to input a plurality of acoustic signals obtained by a plurality of microphones arranged at different positions;
a frequency decomposing unit configured to respectively decompose each acoustic signal into a plurality of frequency components, and for each frequency component, generate frequency decomposition information for which a signal level and a phase have been associated;
a phase difference computing unit configured to compute a phase difference between two predetermined pieces of the frequency decomposition information, for each corresponding frequency component;
a two-dimensional data converting unit configured to convert into two dimensional data made up of point groups arranged on a two-dimensional coordinate system having a frequency component function as a first axis and a phase difference function as a second axis;
a voting unit configured to perform Hough transform on the point groups, generate a plurality of loci respectively corresponding to each of the point groups in a Hough voting space, and when adding a voting value to a position in the Hough voting space through which the plurality of loci passes, perform addition by varying the voting value based on a level difference between first and second signal levels respectively indicated by the two pieces of frequency decomposition information; and
a shape detecting unit configured to retrieve a position where the voting value becomes maximum to detect, from the two-dimensional data, a shape which corresponds to the retrieved position, which indicates a proportional relationship between the frequency component and the phase difference, and which is used to estimate a sound source direction of each of the acoustic signals. - View Dependent Claims (2, 3, 4)
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5. An acoustic signal processing method comprising:
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inputting a plurality of acoustic signals obtained by a plurality of microphones arranged at different positions;
decomposing each acoustic signal into a plurality of frequency components, and for each frequency component, generating frequency decomposition information for which a signal level and a phase have been associated, for each of the acoustic signals;
computing a phase difference between two predetermined pieces of the frequency decomposition information, for each corresponding frequency component;
convert into two dimensional data made up of point groups arranged on a two-dimensional coordinate system having a frequency component function as a first axis and a phase difference function as a second axis;
performing Hough transform on the point groups, generating a plurality of loci respectively corresponding to each of the point groups in a Hough voting space, and when adding a voting value to a position in the Hough voting space through which the plurality of loci passes, performing addition by varying the voting value based on a level difference between first and second signal levels respectively indicated by the two pieces of frequency decomposition information; and
retrieving a position where the voting value becomes maximum to detect, from the two-dimensional data, a shape which corresponds to the retrieved position, which indicates a proportional relationship between the frequency component and the phase difference, and which is used to estimate a sound source direction of each of the acoustic signals. - View Dependent Claims (6, 7, 8)
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9. A computer readable medium storing an acoustic signal processing program for causing a computer to execute instructions to perform steps of:
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inputting a plurality of acoustic signals obtained by a plurality of microphones arranged at different positions;
decomposing each acoustic signal into a plurality of frequency components, and for each frequency component, generating frequency decomposition information for which a signal level and a phase have been associated for each of the acoustic signals;
compute a phase difference between two predetermined pieces of the frequency decomposition information, for each corresponding frequency component;
convert into two dimensional data made up of point groups arranged on a two-dimensional coordinate system having a frequency component function as a first axis and a phase difference function as a second axis;
performing Hough transform on the point groups, generating a plurality of loci respectively corresponding to each of the point groups in a Hough voting space, and when adding a voting value to a position in the Hough voting space through which the plurality of loci passes, performing addition by varying the voting value based on a level difference between first and second signal levels respectively indicated by the two pieces of frequency decomposition information; and
retrieving a position where the voting value becomes maximum to detect, from the two-dimensional data, a shape which corresponds to the retrieved position, which indicates a proportional relationship between the frequency component and, the phase difference, and which is used to estimate a sound source direction of each of the acoustic signals. - View Dependent Claims (10, 11, 12)
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Specification