Adaptive Weiner filtering using line spectral frequencies
First Claim
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1. A method of filtering a stream of sampled acoustic signals, comprising the steps of:
- (a) partitioning a the stream of sampled acoustic signals into a sequence of frames;
(b) Fourier transforming said flames the frames using processing circuitry to yield a sequence of transformed frames;
(c) applying a generalized Wiener filter to said the transformed frames to yield a sequence of filtered transformed frames, wherein said the filter uses power spectrum estimates from LSFs line spectral frequencies (LSFs) defined as weighted sums of LSFs of a codebook of LSFs with the weights determined by the LSFs of said the transformed frames; and
(d) inverse Fourier transforming said sequence of filtered transformed frames to yield a sequence of filtered frames.
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Abstract
An acoustic noise suppression filter including attenuation filtering with a noise-free estimate based on a codebook of line spectral frequencies.
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Citations
11 Claims
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1. A method of filtering a stream of sampled acoustic signals, comprising the steps of:
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(a) partitioning a the stream of sampled acoustic signals into a sequence of frames; (b) Fourier transforming said flames the frames using processing circuitry to yield a sequence of transformed frames; (c) applying a generalized Wiener filter to said the transformed frames to yield a sequence of filtered transformed frames, wherein said the filter uses power spectrum estimates from LSFs line spectral frequencies (LSFs) defined as weighted sums of LSFs of a codebook of LSFs with the weights determined by the LSFs of said the transformed frames; and (d) inverse Fourier transforming said sequence of filtered transformed frames to yield a sequence of filtered frames. - View Dependent Claims (2, 3)
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4. A method of noise suppression filtering for a sequence of frames of noisy speech, comprising:
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filtering a frame of noisy speech that includes the sub-steps of; estimating a noise power spectrum, PNOISE(ω
), of the frame of noisy speech, wherein the variable ω
is the discrete frequency;computing a noisy speech power spectrum for the frame of noisy speech using processing circuitry; smoothing noisy speech power spectrum with respect to the variable ω
to yield a smoothed noisy speech power spectrum, PSMOOTHEDNOISYSPEECH(ω
), for the frame of noisy speech;defining a noise-suppression filter using the noisy speech power spectrum, and the smoothed noisy speech power spectrum; filtering the frame of noisy speech with the noise suppression filter; and repeating the step of filtering for each frame of noisy speech for a plurality of frames of noisy speech. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11)
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Specification