Echo Suppression in Audio Mixing Systems

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Solution Overview

Problem

Audio mixing systems in communication devices face challenges with audible distortions such as echoes and local device alert sounds being mixed with communication audio, leading to distracting noise for far-end users.

Innovation Solution

A system and method that uses an echo suppressor to mitigate echoes and a gain adjuster to control signal levels, allowing a designated audio signal to be mixed with the suppressed input audio signal, creating an uplink audio signal free from artifacts introduced by transducers and microphones, while also enabling user-controlled signal adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the speaker reproduces audio into an acoustic space and the microphone captures audio from the acoustic space, then communication between users is facilitated, but audible distortions including echoes occur

Engineering Contradiction:
Improvecommunication facilitationVSAvoidaudible distortions and echoes
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies echo cancellation technology that takes the harmful echo signal captured by the microphone and processes it through signal processing to generate an anti-echo signal. This anti-echo signal is then subtracted from the captured audio to eliminate the distortion, effectively converting the harmful echo into a beneficial cancellation effect that improves communication quality

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of operation

If local device alert sounds are mixed with communication audio, then device alerts are heard, but far-end users experience distracting noise

Engineering Contradiction:
Improvelocal alert notificationVSAvoiddistracting noise for far-end users
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent implements a detection mechanism that identifies when local device alert sounds are being played through the speaker. When detected, the system extracts and removes these alert sound components from the audio signal that is transmitted to the far-end user. This allows local users to hear alerts while preventing them from becoming distracting noise for remote participants

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2779609B1Sharing a designated audio signal
Publication Date: 2019.09.18 2236008 ONTARIO INC
  • EP2779609B1 patent drawingFigure 1
  • EP2779609B1 patent drawingFigure 2
  • EP2779609B1 patent drawingFigure 3

AI summary

A system and method for sharing a designated audio signal may reproduce the designated audio signal via transducer into an acoustic space. The designated audio signal may be a recorded audio signal, an encoded audio signal, a streamed audio signal and an audio signal component of a multi-media content item. An input audio signal may be received representing a sound field in the acoustic space. One or more microphones may receive the input audio signal. A component contributed by the reproduced designated audio signal may be suppressed in the input audio signal. An echo suppressor may suppress the recaptured designated audio signal. The designated audio signal may be mixed with the suppressed input audio signal to generate an uplink audio signal. The designated audio signal mixed with the suppressed input audio signal may not include artifacts caused by the transducer, the microphone and the acoustic space.