Distributed Audio Echo Cancellation for User-Proximate Devices

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Solution Overview

Problem

Existing audio systems struggle to effectively manage multiple audio devices in a shared environment, leading to challenges in improving the Signal to Echo Ratio (SER) for accurate voice capture and output, particularly when multiple devices are proximate to the user.

Innovation Solution

Implementing a system that coordinates audio devices to dynamically adjust audio processing based on user location and context, including turning down audio output from devices closest to the user to enhance SER, while maintaining spatial imaging and user zone estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple audio devices are deployed proximate to the user, then audio coverage and accessibility are improved, but echo interference increases and Signal to Echo Ratio deteriorates

Engineering Contradiction:
Improveaudio coverageVSAvoidSignal to Echo Ratio
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adjusts audio processing parameters based on real-time detection of user proximity to different audio devices. When a device is detected to be proximate to the user, the system applies echo cancellation control to that specific device, making the echo suppression behavior adaptive and dynamic rather than static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies different audio processing treatments to different audio devices based on their spatial relationship with the user. Devices proximate to the user receive enhanced echo cancellation, while other devices maintain normal operation, creating localized quality adjustments rather than uniform treatment across all devices.

Inventive Principle:
Principle #3Local quality

2Reliability

If echo cancellation is applied to all audio devices, then echo interference is reduced, but spatial imaging and audio delivery accuracy deteriorate

Engineering Contradiction:
Improveecho cancellationVSAvoidspatial imaging
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system applies echo cancellation control selectively only to audio devices detected to be proximate to the user, rather than uniformly to all devices. This localized approach ensures that echo suppression is applied where most needed while preserving the audio quality and spatial imaging characteristics of other devices in the audio environment.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The echo cancellation control is dynamically activated only when a user proximate to a specific audio device is detected. This dynamic conditioning allows the system to adaptively apply echo suppression based on real-time spatial conditions, maintaining spatial imaging accuracy by avoiding unnecessary processing on distant devices.

Inventive Principle:
Principle #15Dynamics

3Reliability

If audio processing is adjusted based on user location, then Signal to Echo Ratio is improved, but system complexity increases

Engineering Contradiction:
ImproveSERVSAvoidaudio processing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The audio environment is segmented into regions based on user proximity detection. The system identifies which audio devices are located in the proximate region and applies echo cancellation control only to those devices, dividing the complex task of audio processing into manageable segments rather than attempting uniform processing across the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses audio signals themselves to detect user proximity and trigger appropriate processing. By analyzing the audio environment and detecting characteristics indicative of user proximity, the system autonomously determines when to apply echo cancellation control without requiring external input or complex manual configuration.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4005228B1Acoustic echo cancellation control for distributed audio devices
Publication Date: 2025.08.27 DOLBY LABORATORIES LICENSING CORP
  • EP4005228B1 patent drawingFigure 1A
  • EP4005228B1 patent drawingFigure 1B
  • EP4005228B1 patent drawingFigure 2A

AI summary

An audio processing method may involve receiving output signals from each microphone of a plurality of microphones in an audio environment, the output signals corresponding to a current utterance of a person and determining, based on the output signals, one or more aspects of context information relating to the person, including an estimated current proximity of the person to one or more microphone locations. The method may involve selecting two or more loudspeaker-equipped audio devices based, at least in part, on the one or more aspects of the context information, determining one or more types of audio processing changes to apply to audio data being rendered to loudspeaker feed signals for the audio devices and causing one or more types of audio processing changes to be applied. In some examples, the audio processing changes have the effect of increasing a speech to echo ratio at one or more microphones.