Voice Processing Attenuating Remote Echo in Double-Talk

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Solution Overview

Problem

Existing echo cancellation systems fail to effectively suppress residual echoes in double-talk states, leading to weakened near-end voice signals and compromised communication quality due to non-linear processor (NLP) limitations and automatic gain control (AGC) amplification of residual echoes.

Innovation Solution

A method and device that detect the communication system's working state, attenuate remote-end voice signals, perform echo processing to obtain near-end and residual echo signals, apply non-linear suppression, and control gain to effectively suppress residual echoes, thereby improving communication quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If NLP is used to suppress residual echoes, then echo suppression capability is improved, but near-end voice signal is weakened in double-talk state

Engineering Contradiction:
Improveresidual echo suppressionVSAvoidnear-end voice signal quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The system performs preliminary classification of the working state (single-talk, double-talk, or silent state) before applying NLP processing. By detecting the working state in advance and only enabling NLP in single-talk states, the system avoids weakening near-end voice signals during double-talk while still suppressing residual echoes when appropriate.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The NLP processing is dynamically enabled or disabled based on the detected working state. The system transitions between different processing modes (NLP enabled/disabled) according to real-time state detection, making the echo suppression adaptive to current communication conditions rather than applying a fixed processing approach.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If AGC is added to amplify near-end voice signal, then voice signal quality is improved, but residual echoes are also amplified

Engineering Contradiction:
Improvenear-end voice signal qualityVSAvoidresidual echo amplification
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The system performs preliminary working state detection to determine whether the current state is single-talk or double-talk before enabling AGC. By classifying the state in advance, the system ensures AGC is only activated when near-end speech is present and echoes are not simultaneously generated, preventing echo amplification.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the working state detector to control AGC activation. The detection result feeds back to the AGC module, creating a closed-loop control system that enables or disables gain control based on real-time analysis of the communication state, thereby preventing residual echo amplification.

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If self-adapting filter is used for echo cancelation, then linear echo suppression is improved, but non-linear residual echoes remain

Engineering Contradiction:
Improvelinear echo suppressionVSAvoidnon-linear residual echoes
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The echo cancellation process is segmented into two distinct stages: first the self-adapting filter handles linear echoes, then NLP processes non-linear residual echoes. This segmentation allows each processing stage to specialize in different types of echo components, improving overall cancellation effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

NLP acts as an intermediary processing stage between the self-adapting filter and the final output. It receives the signal after linear echo cancellation and specifically targets non-linear residual echoes, serving as a mediator that bridges the gap left by linear filtering alone.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS11587574B2Voice processing method, apparatus, electronic device, and storage medium
Publication Date: 2023.02.21 BEIJING DAJIA INTERNET INFORMATION TECH CO LTD
  • US11587574B2 patent drawing
  • US11587574B2 patent drawing
  • US11587574B2 patent drawing

AI summary

Provided in the present disclosure are a voice processing method, an apparatus, an electronic device, and a storage medium, the method comprising: detecting the working state of a current call system, and when the working state is a two-end speaking state or a remote-end speaking state, performing compression processing on a subsequent remote-end voice signal, acquiring a near-end voice signal by means of a microphone, performing echo processing on the basis of the near-end voice signal and the compression-processed remote-end voice signal to obtain an echo-processed near-end voice signal and a remaining echo signal, performing non-linear suppression processing on the near-end voice signal and the remaining echo signal, and performing gain control on the suppression-processed near-end voice signal.