Method and apparatus for speech detection using time-frequency variance
AssigneeMotorola, Inc.
InventorsChangxue Ma, Mark Randolph
Life of this patent
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Abstract
Speech presence is detected by first bandpass filtering (141, 143, 145) the speech to split it into banks of sub-bands. A matrix of shift registers (150) store each sub-band of speech. A power determining circuit (259) then determines individual power measurements of the speech stored in each shift register element. A variance combining circuit (160) combines the individual power measurements to provide a variance for the individual shift registers. A comparitor circuit (170) finally compares the variance with at least one threshold to indicate whether speech is detected.
Claims10
A speech presence detection apparatus, comprising:
- a plurality of bandpass filters for splitting speech into a bank of sub-bands;
- a plurality of shift registers each connected to and associated with one of the bandpass filters for storing the speech of a corresponding sub-band in register elements;
- a power determining circuit for determining individual power measurements of the speech stored in each register element;
- a variance combining circuit for combining the individual power measurements to provide a variance for the individual registers;
- and
- a comparitor circuit for comparing the variance with a threshold to indicate whether speech is detected.
A method of detecting the presence of speech, comprising the steps of:
- (a) calculating a plurality of power samples of speech, each power sample corresponding to a frequency sub-band and time frame of the speech;
- and
- (b) calculating a variance of the plurality of power samples;
- and
- (c) comparing the variance with at least one threshold to indicate whether speech is detected.
An apparatus for detecting the presence of speech, comprising:
- means for calculating a plurality of power samples of speech, each power sample corresponding to a frequency sub-band and time frame of the speech;
- means for calculating a variance of the plurality of power samples;
- and
- means for comparing the variance with at least one threshold to indicate whether speech is detected.
Dependencies are inferred from the claim text.