Acoustic Echo Path Change Detection Using Dual Domain Analysis
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Solution Overview
Problem
Existing acoustic echo path change detectors in voice communication systems face a trade-off between speed and accuracy, leading to ineffective echo cancellation during changes in the acoustic echo path, such as when objects are moved near the microphone or speaker.
Innovation Solution
The proposed solution involves a dual analysis approach combining time domain and frequency domain methods to detect changes in the acoustic echo path, using cross-correlation and auto-regressive moving average (ARMA) functions to rapidly identify changes, and switching the echo canceller to a rapid adaptation mode when necessary, thereby improving echo cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a prior art acoustic echo path change detector is designed to be fast, then the detection speed is improved, but the detection accuracy deteriorates
Solution Approach 1:
The patent divides the echo path change detection process into two independent segments: time domain analysis and frequency domain analysis. Each segment uses different detection algorithms optimized for their respective domains. The time domain analysis provides fast initial detection while the frequency domain analysis provides accurate confirmation, resolving the speed-accuracy tradeoff by segmentation.
Solution Approach 2:
The patent transitions from single-domain detection to multi-domain detection by analyzing echo path changes in both time domain and frequency domain. This dimensional expansion allows the system to leverage the strengths of each domain: speed from time domain and accuracy from frequency domain, simultaneously achieving both fast and accurate detection.
2Measurement precision
If the acoustic echo canceller operates in steady state mode, then the acoustic estimation accuracy is improved, but the response to changes becomes slow
Solution Approach 1:
The patent implements a feedback mechanism where the dual-domain change detector continuously monitors the acoustic echo path and provides feedback signals to the acoustic echo canceller. When changes are detected, the feedback triggers a mode switch from steady state to rapid adaptation, ensuring the canceller responds quickly while maintaining accuracy through continuous monitoring.
Solution Approach 2:
The patent makes the acoustic echo canceller dynamic by enabling switching between two operational modes: steady state mode for accurate estimation during normal operation, and rapid adaptation mode for fast response when changes are detected. This dynamic adaptability resolves the contradiction between accuracy and response speed.
Data Source
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AI summary
An acoustic echo path change detection apparatus constituted of: a time domain path change detection functionality arranged to: detect a change in a near-end acoustic echo path responsive to a time domain analysis of a near-end signal and a signal output by an acoustic echo canceller; and output an indication of the detected change, a frequency domain path change detection functionality arranged to: detect a change in the near-end acoustic echo path responsive to a frequency domain analysis of a far-end signal and the signal output by the acoustic echo canceller; and output an indication of the detected change, and a combination path change detection functionality arranged to: determine a first function of the output indication of the time domain path change detection functionality and the output indication of the frequency domain path change detection functionality; and output the determined first function.