Audio Decorrelator Phase Shifting for Echo Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Audio apparatuses face challenges in effectively canceling acoustic echoes when the correlation between signals output through multiple speakers is high, leading to residual echoes that hinder voice recognition operations.
Innovation Solution
An audio signal processing method that employs a decorrelator to generate decorrelated signals by adjusting phase shifting values based on the correlation difference between audio signals, reducing the phase shifting value when the phase difference is great and setting it to 0 or a predetermined limit value, and using an echo filter unit to cancel echo signals, thereby improving voice recognition accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic signals are output through multiple speakers with high correlation, then the audio quality is maintained, but the echo cancellation filter diverges and residual echo remains
Solution Approach 1:
The decorrelator applies phase shifting to audio signals before they are output through speakers, proactively reducing correlation between channels in advance. This preliminary action prevents the echo cancellation filter from diverging and eliminates residual echo, enabling reliable voice recognition operations.
Solution Approach 2:
The system changes the phase parameter of audio signals by applying phase shifting values through the decorrelator. This parameter modification reduces the correlation between acoustic signals from multiple speakers, allowing the echo cancellation filter to converge properly and eliminate residual echo effectively.
2Reliability
If phase shifting value is increased to reduce correlation, then echo cancellation improves, but audio signal distortion increases
Solution Approach 1:
The decorrelator dynamically adjusts phase shifting values based on the correlation between audio signals from different speakers. By adaptively changing the phase shifting amount, the system reduces correlation enough to prevent filter divergence while minimizing audio signal distortion, achieving a balance between voice recognition accuracy and audio fidelity.
Solution Approach 2:
The system uses feedback from the correlation calculation to adjust phase shifting values. The decorrelator calculates correlation between audio signals and applies appropriate phase shifting to reduce this correlation, creating a feedback loop that optimizes both echo cancellation effectiveness and audio signal quality.
Data Source
AI summary
An audio apparatus including a decorrelator for generating decorrelated signals by applying a phase shifting value adjusted based on a correlation difference between audio signals included in a multi-channel signal to the audio signals; and a speaker set including at least two speakers for outputting acoustic signals corresponding to the decorrelated signals.