Multi-Channel Audio Processing for Acoustic Echo De-Localization
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Solution Overview
Problem
Existing acoustic echo cancellation techniques in multi-channel audio processing produce artefacts and fail to effectively suppress the spatiality of acoustic echoes, especially in low-latency communications.
Innovation Solution
The apparatus suppresses spatiality of acoustic echoes by de-localizing the sound source, spreading it across multiple audio channels, and using adaptive filtering and echo cancellation artefact masking to make the sound source more diffuse and less directional.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If acoustic echo cancellation is applied to captured multi-channel audio, then acoustic echo is reduced, but acoustic echo cancellation artefacts are produced
Solution Approach 1:
The patent uses the acoustic echo cancellation artefacts themselves as a masking signal to suppress the perception of residual acoustic echo. By de-localizing the artefact signal and spreading it across multiple audio channels, the artefacts mask the remaining echo without creating noticeable degradation, effectively converting a harmful byproduct into a beneficial masking mechanism
Solution Approach 2:
The patent applies different processing to different components of the audio signal. Locally generated sound sources maintain their spatial integrity and directionality, while acoustic echo and its cancellation artefacts are de-localized and spread across channels. This selective application of de-localization based on signal origin resolves the contradiction by preserving quality where needed while suppressing echo artefacts
2Object-affected harmful factors
If acoustic echo cancellation is applied to captured multi-channel audio, then acoustic echo is reduced, but spatial audio integrity is degraded
Solution Approach 1:
The system identifies and differentiates between locally generated sound sources and acoustic echo. Local sound sources maintain their original spatial characteristics and directionality, while only the acoustic echo components are de-localized. This selective processing preserves spatial audio integrity for legitimate content while still achieving echo suppression
3Object-affected harmful factors
If de-localizing is applied to sound source representing acoustic echo, then perceived directionality is reduced, but sound diffusion is increased
Solution Approach 1:
The patent applies de-localization selectively only to acoustic echo components identified through analysis of the audio signal and acoustic model, while preserving the spatial characteristics of local sound sources. This targeted approach reduces the perceived directionality of echo without unnecessarily altering the spatial composition of legitimate audio content
Solution Approach 2:
The system dynamically adjusts the degree of de-localization based on the identified acoustic echo characteristics and spatial parameters. By changing spatial parameters selectively for echo components while maintaining original parameters for local sources, the system achieves reduced perceived directionality of echo while preserving overall spatial audio integrity
Data Source
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AI summary
An apparatus comprising means for: rendering a received output audio signal via at least one audio output; locally capturing multi-channel input audio, wherein the multi-channel input audio comprises multiple audio input channels comprising at least: a first audio input channel comprising audio captured at a first microphone; and a second audio input channel comprising audio captured at a second microphone; and processing the multi-channel input audio to produce a multi-channel input audio signal representing local captured audio, wherein processing the multi-channel input audio comprises suppressing spatiality of an acoustic echo wherein suppressing the spatiality of an acoustic echo comprises de-localizing a sound source representing the acoustic echo