Conference Audio Echo Suppression via Signal Comparison

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Solution Overview

Problem

Computing devices within audio output range of each other often experience acoustic echoes during video calls, degrading audio quality and user experience due to feedback loops caused by microphone and speaker interactions.

Innovation Solution

Implementing a system where user devices connect through a local central control device and a conference call server, allowing devices to compare audio signals received from the server with those received from nearby devices via the central control device, and preventing echo by blocking output of matching signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple computing devices are connected to the same video call within the same space, then audio coverage and communication capability are improved, but acoustic echoes and feedback loops occur degrading audio quality

Engineering Contradiction:

Improveaudio coverageVSAvoidacoustic echo

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system implements a feedback mechanism where each device monitors its own microphone input for audio signals that match what it is currently outputting through its speaker. When a match is detected, the device adjusts its output to prevent the feedback loop, thereby eliminating echo while maintaining multi-device connectivity

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent introduces a server as an intermediary that coordinates audio signal management across multiple devices. The server receives audio signals from participants, determines which devices should output which signals, and prevents echo by controlling the audio routing and output permissions of each device based on the detected audio environment

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If audio signals are transmitted through multiple devices in close proximity, then communication reach is improved, but feedback loops are created affecting video call quality

Engineering Contradiction:

Improvecommunication reachVSAvoidvideo call quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Each device continuously monitors its microphone for audio signals that match its speaker output, creating a feedback detection mechanism. When feedback is detected, the system automatically adjusts audio routing or mutes the problematic output channel, maintaining communication reach while ensuring call quality

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary audio signal comparison before allowing output through speakers. By checking whether an audio signal matches what is already being output by another device in the same space, the system prevents feedback loops before they occur, ensuring reliable video call quality from the start

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12225161B2Blocking conference audio output

Publication Date: 2025.02.11 HEWLETT PACKARD DEVELOPMENT COMPANY LP

AI summary

An example electronic device includes a network communication interface to connect to a conference server, a central control device communication interface to connect to a local central control device, a microphone and a processor. The processor is to receive audio at the microphone and send the audio to the local central control device and to the conference server. The processor is to send the audio to the local central control device such that it is received by a nearby electronic device before the audio is received from the conference server by the nearby electronic device.