Speech feature extraction system
AssigneeYigal Brandman
InventorYigal Brandman
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Abstract
The present invention provides a speech feature extraction system suitable for use in a speech recognition system or other voice processing system that extracts features related to the frequency and amplitude characteristics of an input speech signal using a plurality of complex band pass filters and processing the outputs of adjacent band pass filters. The band pass filters can be arranged according to linear, logarithmic or mel-scales, or a combination thereof.
Claims38
Apparatus for use in a speech processing system for extracting features from an input speech signal having frequency and amplitude characteristics, the apparatus comprising:
- first and second band pass filters adapted to receive the input speech signal and providing respectively, first and second signals;
- a conjugate circuit coupled to the second band pass filter and providing a third signal that is the conjugate of the second signal;
- a multiplier coupled to the first band pass filter and to the conjugate circuit and providing a fourth signal that is the product of the first and third signals;
- and
- filter means coupled to the multiplier for providing a fifth signal related to the frequency characteristics of the input signal, and a sixth signal related to amplitude characteristics of the input signal.
A method for extracting features from an input speech signal for use in a speech processing device, the method comprising:
- separating the input signal into a first signal in a first frequency band and a second signal in a second frequency band;
- providing a conjugate of the first signal;
- multiplying the conjugate of the first signal with the second signal to provide a third signal;
- and
- processing the third signal to generate a frequency component related to frequency features in the input speech signal and an amplitude component related to amplitude features in the input speech signal.
Dependencies are inferred from the claim text.