Detection of periodicity information from an audio signal
First Claim
1. A method of generating periodicity information from an input audio signal, comprising the steps of:
- generating a pre-processed signal by applying low pass and non-linear filtering to remove information from the input audio signal, wherein the removed information is not indicative of speech pitch information;
transforming the pre-processed signal in accordance with an adaptive threshold algorithm to generate a detection signal having waveform segments whose peaks are separated by a pitch period of the input audio signal;
determining a period between peaks in the detection signal to generate the periodicity information; and
using information about the period between the peaks in the detection signal to adapt a scaling value that is used by the adaptive threshold algorithm when processing a subsequent pre-processed signal.
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Abstract
A waveform-based technique for generating periodicity information from an input signal includes generating a pre-processed signal by applying low pass and non-linear filtering to the input signal, wherein the pre-processed signal has highlighted speech pitch tracks. An adaptive threshold algorithm is applied to the pre-processed signal to generate a detection signal having waveform segments whose peaks are separated by a pitch period of the input signal. A period between peaks in the detection signal is determined that indicates the periodicity information. Information about the period between the peaks in the detection signal is then used to adapt a scaling value to be used by the adaptive threshold algorithm in a subsequent step. The periodicity information may be utilized in a voice activity detector in a telephonic communications system.
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Citations
26 Claims
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1. A method of generating periodicity information from an input audio signal, comprising the steps of:
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generating a pre-processed signal by applying low pass and non-linear filtering to remove information from the input audio signal, wherein the removed information is not indicative of speech pitch information; transforming the pre-processed signal in accordance with an adaptive threshold algorithm to generate a detection signal having waveform segments whose peaks are separated by a pitch period of the input audio signal; determining a period between peaks in the detection signal to generate the periodicity information; and using information about the period between the peaks in the detection signal to adapt a scaling value that is used by the adaptive threshold algorithm when processing a subsequent pre-processed signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus for generating periodicity information from an input audio signal, comprising:
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means for generating a pre-processed signal by applying low pass and non-linear filtering to remove information from the input audio signal, wherein the removed information is not indicative of speech pitch information; means for transforming the pre-processed signal in accordance with an adaptive threshold algorithm to generate a detection signal having waveform segments whose peaks are separated by a pitch period of the input audio signal; means for determining a period between peaks in the detection signal to generate the periodicity information; and means for using information about the period between the peaks in the detection signal to adapt a scaling value that is used by the adaptive threshold algorithm when processing a subsequent pre-processed signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification