Beamformed Acoustic Echo Cancellation for Dynamic Participant Tracking

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Solution Overview

Problem

Existing video conferencing systems face challenges in effectively canceling acoustic echoes due to the dynamic nature of participant locations within a room, leading to inefficient computational resources and reduced sound quality.

Innovation Solution

A system and method utilizing a microphone array with beamforming techniques to adaptively track participant locations, determine acoustic echo cancellation parameters based on room impulse responses, and perform echo cancellation on channels corresponding to the number of participants, rather than the total number of microphones, thereby optimizing computational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If acoustic echo cancellation is performed for all microphone channels, then echo cancellation coverage is improved, but computational complexity increases

Engineering Contradiction:
Improveecho cancellation coverageVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the echo cancellation task by creating separate echo cancellers only for channels where participants are detected, rather than processing all microphone channels uniformly. This segmentation reduces computational complexity while maintaining effective echo cancellation coverage for relevant channels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by performing echo cancellation only on the necessary subset of channels corresponding to participant locations, rather than applying it excessively to all channels. This optimizes computational resources while achieving sufficient echo cancellation performance.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If the number of echo cancellers is increased to match the total number of microphones, then echo cancellation completeness is improved, but computational efficiency deteriorates

Engineering Contradiction:
Improveecho cancellation completenessVSAvoidcomputational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements a dynamic approach where the number of echo cancellers adapts based on the detected participant locations. The system dynamically adjusts the number of active echo cancellers to match the number of participants, optimizing computational efficiency while maintaining cancellation completeness for relevant channels.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of echo canceller quantity from a fixed value (total microphone count) to a variable value (participant count). This parameter change allows the system to optimize computational efficiency by adjusting the number of echo cancellers based on actual usage requirements.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If beamforming is used to capture audio from specific locations, then audio directionality is improved, but system complexity increases

Engineering Contradiction:
Improveaudio directionalityVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent achieves multi-functionality by using the beamformer to simultaneously capture audio signals and determine participant locations. This single component performs multiple functions, improving audio directionality while avoiding the need for separate location detection systems, thus limiting the increase in system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances sound quality by reducing acoustic echoes while maintaining computational efficiency, even with varying participant locations, using a reduced number of echo cancellers proportional to the number of participants.

Implementation Method 1

capturing an audio signal received from the location of the person using beamforming

Methodology Applied
Scientific EffectBeamforming:

Implementation Method 2

perform acoustic echo cancellation on the audio signal using the acoustic echo cancellation parameter

Methodology Applied
Scientific EffectAcoustic echo cancellation: Echo

Data Source

PatentEP3994874B1Acoustic echo cancellation
Publication Date: 2025.11.19 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3994874B1 patent drawingFigure 1
  • EP3994874B1 patent drawingFigure 2
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AI summary

Acoustic echo cancellation for a video conference system is described. A location of a person in a room can be determined. An audio signal received from the location of the person can be captured using beamforming. An acoustic echo cancellation parameter can be determined based in part on the audio signal captured from the location of the person. Acoustic echo cancellation can be performed on the audio signal using the acoustic echo cancellation parameter.