Binaural signal processing techniques
First Claim
1. A method, comprising:
- providing a first signal from a first acoustic sensor and a second signal from a second acoustic sensor spaced apart from the first acoustic sensor, the first signal and the second signal each corresponding to two or more acoustic sources, said acoustic sources including a plurality of interfering sources and a desired source;
localizing the interfering sources from the first and second signals to provide a corresponding number of interfering source signals each corresponding to a different one of the interfering sources and each including a plurality of frequency components, the components each corresponding to a different frequency; and
suppressing one or more different frequency components of each of the interfering source signals to reduce noise.
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Abstract
A desired acoustic signal is extracted from a noisy environment by generating a signal representative of the desired signal with processor (30). Processor (30) receives aural signals from two sensors (22, 24) each at a different location. The two inputs to processor (30) are converted from analog to digital format and then submitted to a discrete Fourier transform process to generate discrete spectral signal representations. The spectral signals are delayed to provide a number of intermediate signals, each corresponding to a different spatial location relative to the two sensors. Locations of the noise source and the desired source, and the spectral content of the desired signal are determined from the intermediate signal corresponding to the noise source locations. Inverse transformation of the selected intermediate signal followed by digital to analog conversion provides an output signal representative of the desired signal with output device (90). Techniques to localize multiple acoustic sources are also disclosed. Further, a technique to enhance noise reduction from multiple sources based on twosensor reception is described.
149 Citations
45 Claims
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1. A method, comprising:
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providing a first signal from a first acoustic sensor and a second signal from a second acoustic sensor spaced apart from the first acoustic sensor, the first signal and the second signal each corresponding to two or more acoustic sources, said acoustic sources including a plurality of interfering sources and a desired source;
localizing the interfering sources from the first and second signals to provide a corresponding number of interfering source signals each corresponding to a different one of the interfering sources and each including a plurality of frequency components, the components each corresponding to a different frequency; and
suppressing one or more different frequency components of each of the interfering source signals to reduce noise. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system, comprising:
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a pair of spaced apart acoustic sensors each arranged to detect two or more differently located acoustic sources and correspondingly generate a pair of input signals, said acoustic sources including a desired source and a plurality of interfering sources;
a delay operator responsive to said input signals to generate a number of delayed signals therefrom;
a localization operator responsive to said delayed signals to localize said interfering sources relative to location of said sensors and provide a plurality of interfering source signals each representative of a corresponding one of said interfering sources, said interfering source signals each being represented in terms of a plurality of frequency components, said components each corresponding to a different frequency;
an extraction operator responsive to said interfering source signals to suppress at least one of said frequency components of each of said interfering source signals and extract a desired signal corresponding to said desired source, said at least one of said frequency components being different for each of said interfering source signals; and
an output device responsive to said desired signal to provide an output corresponding to said desired source. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method, comprising:
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positioning a first acoustic sensor and a second acoustic sensor to detect a plurality of differently located acoustic sources;
generating a first signal corresponding to said sources with said first sensor and a second signal corresponding to said sources with said second sensor;
providing a number of delayed signal pairs from the first and second signals, the delayed signal pairs each corresponding to one of a number of positions relative to the first and second sensors; and
localizing the sources as a function of the delayed signal pairs and a number of coincidence patterns, the patterns each corresponding to one of the positions and establishing an expected variation of acoustic source position information with frequency attributable to a source at the one of the positions. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. A system, comprising:
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a pair of spaced apart acoustic sensors each configured to generate a corresponding one of a pair of inputs signals, the signals being representative of a number of differently located acoustic sources;
a delay operator responsive to said input signals to generate a number of delayed signals each corresponding to one of a number of positions relative to said sensors;
a localization operator responsive to said delayed signals to determine a number of sound source localization signals from said delayed signals and a number of coincidence patterns, said patterns each corresponding to one of said positions and relating frequency varying sound source position information caused by ambiguous phase multiples to said one of said positions to improve sound source localization; and
an output device responsive to said localization signals to provide an output corresponding to at least one of said sources. - View Dependent Claims (27, 28, 29, 30, 31)
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32. A system, comprising:
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a pair of spaced apart acoustic sensors each generating a corresponding one of a pair of inputs signals, the signals each being representative of a number of differently located sound sources;
a signal processor responsive to said sensors, said processor including;
(a) a means for providing a number of delayed signals from said input signals, the delayed signals each corresponding to one of a number of positions relative to said first and second sensors;
(b) a means for localizing each of said sound sources to one of said positions as a finction of said delayed signals and a corresponding one of a number of patterns of frequency invariant data corresponding to one of said positions and frequency dependent data corresponding to at least two other of said positions;
(c) a means for suppressing a different frequency component of each of a selected number of said sources causing interference and for extracting a desired signal representative of one of said sources; and
an output device responsive to said desired signal to provide an output corresponding to said one of said sources. - View Dependent Claims (33)
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34. A signal processing system, comprising:
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(a) a first sensor at a first location configured to provide a first signal corresponding to an acoustic signal, said acoustic signal including a desired signal emanating from a selected source and noise emanating from a noise source;
(b) a second sensor at a second location configured to provide a second signal corresponding to said acoustic signal;
(c) a signal processor responsive to said first and second signals to generate a discrete first spectral signal corresponding to said first signal and a discrete second spectral signal corresponding to said second signal, said processor being configured to delay said first and second spectral signals by a number of time intervals to generate a number of delayed first signals and a number of delayed second signals and provide a time increment signal, said time increment signal corresponding to separation of the selected source from the noise source, and said processor being further configured to generate an output signal as a function of said time increment signal; and
(d) an output device responsive to said output signal to provide an output representative of said desired signal. - View Dependent Claims (35, 36, 37, 38, 39, 40)
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41. A method of signal processing, comprising:
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(a) positioning a first and second sensor relative to a first signal source, the first and second sensor being spaced apart from each other, and a second signal source being spaced apart from the first signal source;
(b) providing a first signal from the first sensor and a second signal from the second signal, the first and second signals each being representative of a composite acoustic signal including a desired signal from the first signal source and an unwanted signal from the second signal source;
(c) establishing a number of spectral signals from the first and second signals as a function of a number of frequencies, each of the spectral signals representing a different position relative to the first signal source;
(d) determining a member of the spectral signals representative of position of the second signal source; and
(e) generating an output signal from the member, the output signal being representative of spectral content of the first signal. - View Dependent Claims (42, 43, 44, 45)
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Specification