Voice-activated switch
First Claim
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1. Apparatus for detecting human speech in an audio signal, comprising:
- a single lag autocorrelation unit, that receives a digital signal representative of the audio signal and provides a respective single-lag autocorrelated signal, representative of each received digital signal multiplied by said each received digital signal delayed by the same period of time corresponding to a first formant frequency;
an initial decision unit for providing initial decisions associated with portions of said single-lag autocorrelated signal, wherein an initial decision indicates a talk state if an associated portion of said single-lag autocorrelated signal exceeds a scaled noise value and wherein said initial decision indicates a pause state otherwise; and
a final decision unit that determines when a portion of the audio signal contains human speech according to a plurality of said initial decisions.
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Abstract
Human speech is detected in an audio signal by first providing a single autocorrelated signal indicative of the audio signal multiplied by a time-delayed portion of the audio signal, the delay being an amount of time indicative of a period corresponding to a first formant frequency. Portions of the autocorrelated signal are compared with a scaled noise value. Human speech is detected by examining whether a plurality of portions of the autocorrelated signal exceed the scaled noise value.
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28 Claims
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1. Apparatus for detecting human speech in an audio signal, comprising:
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a single lag autocorrelation unit, that receives a digital signal representative of the audio signal and provides a respective single-lag autocorrelated signal, representative of each received digital signal multiplied by said each received digital signal delayed by the same period of time corresponding to a first formant frequency; an initial decision unit for providing initial decisions associated with portions of said single-lag autocorrelated signal, wherein an initial decision indicates a talk state if an associated portion of said single-lag autocorrelated signal exceeds a scaled noise value and wherein said initial decision indicates a pause state otherwise; and a final decision unit that determines when a portion of the audio signal contains human speech according to a plurality of said initial decisions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. Method of detecting speech in an audio signal, comprising the steps of:
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providing a single autocorrelated signal corresponding to the audio signal multiplied by a portion of the audio signal delayed by only a single-lag period of time corresponding to a first formant frequency; associating a initial decisions with portions of said single-lag autocorrelated signal, wherein an initial decision indicates a talk state if an associated portion of said single-lag autocorrelated signal exceeds a scaled noise value and wherein said initial decision indicates a pause state otherwise; and deeming a portion of the audio signal to contain human speech according to a plurality of initial decisions. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification