NOISE SUPPRESSION BASED UPON BARK BAND WEINER FILTERING AND MODIFIED DOBLINGER NOISE ESTIMATE

Title:

NOISE SUPPRESSION BASED UPON BARK BAND WEINER FILTERING AND MODIFIED DOBLINGER NOISE ESTIMATE

Document Type and Number:

WIPO Patent Application WO/2005/109404

Kind Code:

A3

Abstract:

In a noise suppresser, an input signal is converted to frequency domain by discrete Fourier analysis and divided into Bark bands. Noise is estimated for each band (85). The circuit for estimating noise includes a smoothing filter having a slower time constant for updating the noise estimate during noise than during speech. The noise suppresser further includes a circuit (86) to adjust a noise suppression factor (89) inversely proportional to the signal to noise ratio of each frame of the input signal. A noise estimate is subtracted from the signal in each band. A discrete inverse Fourier transform converts the signals back to the time domain and overlapping and combined windows eliminate artifacts that may have been produced during processing.

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Inventors:

EBENEZER SAMUEL PONVARMA (US)

Application Number:

PCT/US2005/013164

Publication Date:

November 22, 2007

Filing Date:

April 18, 2005

Export Citation:

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Assignee:

ACOUSTIC TECH INC (US)

International Classes:

H04M1/00; G01L3/02; G10L21/02; H04M9/00

Foreign References:

US5706395A	1998-01-06
US5864794A	1999-01-26
US6415253B1	2002-07-02

Other References: