Comfortable noise generator, method for generating comfortable noise, and device for counteracting echo

Abstract

The embodiment of the invention provides a comfortable noise generator, a method for generating a comfortable noise, and a device for counteracting an echo, and belongs to the technical field of voice communication. The generator comprises a background noise estimation module, a white noise generation module, a white noise shaping module and a comfortable noise filling module, wherein the background noise estimation module is used for estimating a frequency spectrum characteristic and an energy level of a present frame signal in a frequency domain when the present frame signal of an input signal is a background noise so as to obtain a frequency spectrum characteristic estimated value and an energy level estimated value; the white noise generation module is used for generating a white noise in the frequency domain; the white noise shaping module is used for shaping the white noise generated by the white noise generation module so as to obtain a comfortable noise according to the obtained frequency spectrum characteristic estimated value and the obtained energy level estimated value, and the frequency spectrum characteristic and the energy level of the obtained comfortable noise are matched with those of the background noise; and the comfortable noise filling module is used for filling the present frame signal of an output frequency domain signal in which a residual echo is suppressed by using the shaped comfortable noise. By the generator, the quality of a voice can be guaranteed.

Description

technical field [0001] The invention relates to the technical field of voice communication, in particular to a comfort noise generator, method and echo cancellation device. Background technique [0002] In modern voice communication systems (such as VOIP, mobile phones, video conferencing systems, etc.), echoes often exist. Currently, AEC (Acoustic Echo Cancellation) modules are installed in voice communication systems to solve echoes and improve dual ability to speak. [0003] Currently as figure 1 The AEC module applied in the communication system shown is as figure 2 As shown, it includes: Adaptive Filter (adaptive filter), NLP (Non-Linear Process, nonlinear processing) and CNG (Comfort NoiseGenerator, comfort noise generator) and other sub-modules, where Adaptive Filter eliminates linear echo, What NLP eliminates is nonlinear echo and residual linear echo. The function of CNG is to compensate the suppressed background noise, make the background noise in speech conti...

AI Technical Summary

Problems solved by technology

[0008] There are at least the following shortcomings in the implementation of this CNG: (1) the spectral characteristics of hoth noise and background noise do not match, mainly because the background noise of near-end speech comes from the surrounding environment, such as printers, air conditioners, etc., so , its spectral characteristics are various and change with time, while the spectral characteristics of hoth noise are fixed (because the filter coefficient in formula (1) is constant), therefore, the spectral characteristics of hoth noise and background noise do not match, It means that there are two kinds of background noises that appear alternately in time in the near-end speech, which will deteriorate the speech quality

(2) The energy level of the hoth noise does not match the background noise, mainly because the hoth noise uses a fixed energy level, while the energy level of the background noise changes with the surrounding environment. Therefore, the hoth noise cannot match the energy of the variable background noise If the level matches, there may be artificially generated "bumpy" noise phenomenon, which will affect the voice quality

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