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Noise suppressor

A noise suppression and noise technology, applied in the field of noise suppression devices, can solve the problems of increasing errors, erroneously suppressing sound components, and deteriorating sound quality.

Inactive Publication Date: 2007-08-29
FUJITSU CONNECTED TECH LTD
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Problems solved by technology

[0030] However, when the caller's voice is input, as shown in FIG. 6, the smoothed amplitude component becomes blunt, and the error between the amplitude component of the voice signal shown by the dotted line and the smoothed amplitude component shown by the solid line ( Hereinafter referred to as "sound estimation error") becomes larger
[0031] As a result, since the suppression coefficient is obtained from the smoothed amplitude component with a large sound estimation error and the estimated noise amplitude, and the input amplitude component is multiplied by the suppression coefficient, the sound component included in the input signal is erroneously suppressed, causing Problem of deterioration of sound quality

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Embodiment Construction

[0078] Embodiments of the present invention will be described below with reference to the drawings.

[0079] Fig. 7 and Fig. 8 show the schematic diagram of the suppression coefficient calculation of the present invention. In the present invention, the smoothing of the input amplitude component is performed before calculating the suppression coefficient as in FIG. 4 .

[0080] In FIG. 7 , the amplitude component |X of the current frame n is used in the amplitude smoothing unit 21 n (f)| and weight coefficient w m (f) Get the smoothed amplitude component P n (f). The suppression coefficient calculation unit 22 smoothes the amplitude component P n (f) and the estimated noise amplitude component μ n (f) Calculate the inhibition coefficient G n (f).

[0081] In FIG. 8 , the weight coefficient calculation section 23 calculates feature quantities (SNR, amplitude of the input signal, etc.) from the input amplitude components, and adaptively controls the weight coefficient w ac...

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Abstract

A noise suppressor comprises frequency dividing means for dividing an input signal into bands and outputting a band signal, amplitude computing means for determining the amplitude component of the band signal, noise estimating means for estimating the amplitude component of the noise contained in the input signal and determining the estimated noise amplitude component for each band, weight coefficient generating means for generating the weight coefficient different in bands, amplitude smoothing means for determining the smoothed ampliture component produced by temporally smoothing the ampliture component of the band signal by using the weight coefficient, suppression amount computing means for determining a suppression coefficient from the smoothed amplitude component and the estimated noise amplitude component for each band, noise suppression means for suppressing the band signal according to the suppression coefficient, and frequency combining means for combining the band signals for which the noise has been suppressed in the bands outputted from the noise suppressing means. While suppressing musical noise, the influence on the sound is minimized, and a stable noise suppression performance is realized.

Description

technical field [0001] The present invention relates to a noise suppression device, and relates to a noise suppression device for reducing noise components from a noise-overlapped sound signal. Background technique [0002] In mobile phone systems and IP (Internet Protocol) phone systems, etc., environmental noise is mixed into the microphone in addition to the caller's voice. As a result, the sound signal becomes harsh, impairing the clarity of the sound. Therefore, conventionally, technologies have been developed to reduce noise components from harsh audio signals and improve call quality (see, for example, Non-Patent Document 1 and Patent Document 1). [0003] FIG. 1 shows a block diagram of an example of a conventional noise suppression device. In this figure, the time-frequency conversion unit 10 converts the input signal x of the current frame n per unit time (frame) n (k) Convert from the time domain k to the frequency domain f, and find the frequency domain signal...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10L21/02G10L21/0208G10L21/0232
CPCG10L21/0208G10L25/18
Inventor 大谷猛松原光良远藤香绪里大田恭士
Owner FUJITSU CONNECTED TECH LTD
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