Method, device and program for extracting and recognizing voice
First Claim
1. A method of extracting voice components from a digital voice signal containing a mixture of voice components and noise components, said method comprising:
- extracting a plurality of kinds of signal components from the digital voice signal containing the mixture of voice components and noise components by using a plurality of digital band-pass filters;
forming a first synthesized signal by synthesizing, according to a first rule having a first probability density function, the extracted signal components, and forming a second synthesized signal by synthesizing, according to a second rule having a second probability density function different from the first rule, the extracted signal components, a respective difference between the first and second probability density functions and a Gaussian distribution being at a maximum; and
selectively producing a synthesized voice signal expressing the feature of the voice components from the first and second synthesized signals;
wherein the first and second rules are determined based on characteristic feature quantities of the first and second synthesized signals,wherein differences between the first synthesized signal and the second synthesized signal and the Gaussian distribution are evaluated to selectively output the one of the first and second synthesized signals having the greatest difference from the Gaussian distribution as the synthesized voice signal.
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Abstract
In a method of extracting voice components free of noise components from voice signals input through a single microphone, a signal-decomposing unit extracts independent signal components from the voice signals input through a single microphone by using a plurality of filters that permit the passage of signal components of different frequency bands. A signal-synthesizing unit synthesizes the signal components according to a first rule to form a first synthesized signal, and synthesizes the signal components according to a second rule to form a second synthesized signal. The first and second rules are so determined that a difference becomes a maximum between the probability density function of the first synthesized signal and the probability density function of the second synthesized signal. An output selection unit selectively produces a synthesized signal having a large difference from the Gaussian distribution between the synthesized signals.
29 Citations
14 Claims
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1. A method of extracting voice components from a digital voice signal containing a mixture of voice components and noise components, said method comprising:
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extracting a plurality of kinds of signal components from the digital voice signal containing the mixture of voice components and noise components by using a plurality of digital band-pass filters; forming a first synthesized signal by synthesizing, according to a first rule having a first probability density function, the extracted signal components, and forming a second synthesized signal by synthesizing, according to a second rule having a second probability density function different from the first rule, the extracted signal components, a respective difference between the first and second probability density functions and a Gaussian distribution being at a maximum; and selectively producing a synthesized voice signal expressing the feature of the voice components from the first and second synthesized signals; wherein the first and second rules are determined based on characteristic feature quantities of the first and second synthesized signals, wherein differences between the first synthesized signal and the second synthesized signal and the Gaussian distribution are evaluated to selectively output the one of the first and second synthesized signals having the greatest difference from the Gaussian distribution as the synthesized voice signal. - View Dependent Claims (2, 3, 4, 5)
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6. An apparatus for selectively extracting voice components from a digital voice signal containing a mixture of voice components and noise components, the apparatus comprising:
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a plurality of digital band-pass filters; extract means for extracting a plurality of kinds of signal components from the mixture of voice components and noise components of the digital voice signal input from an external unit by using the plurality of digital band-pass filters; first synthesizing means for forming a first synthesized signal by synthesizing the signal components extracted by the extract means according to a first rule having a first probability density function; second synthesizing means for forming a second synthesized signal by synthesizing the signal components extracted by the extract means according to a second rule having a second probability density function different from the first rule, a difference between the first and second probability functions and the Gaussian distribution being at a maximum; selective output means for selectively producing a synthesized voice signal expressing the feature of the voice component from the first synthesized signal formed by the first synthesizing means and the second synthesized signal formed by the second synthesizing means; and determining means for determining the first and second rules based on a statistic feature quantity of the first synthesized signal formed by the first synthesizing means and of the second synthesized signal formed by the second synthesizing means, wherein differences between the first synthesized signal and the second synthesized signal and the Gaussian distribution are evaluated to selectively output one of the first synthesized signal and the second synthesized having the greatest difference from the Gaussian distribution as the synthesized voice signal. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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14. An article of manufacture comprising:
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a computer readable medium; and instructions carried on the computer readable medium, the instructions for selectively extracting voice components from a digital voice signal containing a mixture of voice components and noise components, the instructions, when read and executed by a computer, for causing the computer to function as; a plurality of digital band-pass filters; extract means for extracting a plurality of kinds of signal components from the digital voice signal containing the mixture of voice components and noise components input from an external unit by using said plurality of filters first synthesizing means for forming a first synthesized signal by synthesizing the signal components extracted by said extract means according to a first rule having a first probability density function; second synthesizing means for forming a second synthesized signal by synthesizing the signal components extracted by said extract means according to a second rule having a second probability density function different from the first rule, respective difference between the first and second probability density functions and a Gaussian distribution being at a maximum; and selective output means for selectively producing a synthesized voice signal expressing the feature of the voice component based on the first synthesized signal formed by the first synthesizing means and the second synthesized signal formed by the second synthesizing means; and determining means for determining the first and second rules based on the statistic feature quantity of the first synthesized signal formed by the first synthesizing means and of the second synthesized signal formed by the second synthesizing means wherein the respective differences between the first synthesized signal and the second synthesized signal and the Gaussian distribution are evaluated, and the synthesized signal evaluated to have the greatest difference from the Gaussian distribution is selectively output as the synthesized voice signal.
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Specification