Echo Cancellation Adaptation for Music Playback Fading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing echo cancellation methods in communication systems face challenges with fading caused by music and loudspeaker preprocessing, leading to excessive suppression of near-end speech and unreliable signal processing due to time-variant noise levels.
Innovation Solution
The method controls an over-suppression factor based on the far-end signal, setting it to a low value when no activity is detected and increasing it when activity is present, while using the loopback signal for echo path estimation only when there is sufficient signal power, thereby preventing fading and ensuring reliable echo cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If echo cancellation is continuously applied during music playback or loudspeaker preprocessing, then echo suppression is maintained, but near-end speech is excessively suppressed causing fading
Solution Approach 1:
The echo cancellation system dynamically adjusts the suppression factor based on detected signal types. When music or preprocessing is detected, the system reduces or disables echo cancellation to prevent fading of near-end speech. When speech is detected, full echo cancellation is applied. This dynamic adaptation resolves the contradiction by making the suppression level variable rather than fixed.
Solution Approach 2:
The system changes the suppression parameter based on the detected audio content. The suppression factor is adjusted from high (during speech) to low or zero (during music or preprocessing). This parameter change allows the system to maintain echo cancellation reliability during speech while avoiding harmful suppression during non-speech periods.
2Adaptability or versatility
If echo cancellation uses time-variant noise levels for processing, then adaptation to changing environments is achieved, but signal processing becomes unreliable
Solution Approach 1:
The system segments the audio signal processing into distinct phases: detection phase (identifying signal type and noise levels), decision phase (determining whether to apply echo cancellation), and execution phase (applying appropriate suppression). This segmentation allows the system to adapt to environmental changes while maintaining reliability by making informed decisions at each stage rather than continuously adapting.
Solution Approach 2:
The system performs preliminary detection and analysis of the audio signal and noise levels before applying echo cancellation. By pre-assessing the signal conditions and identifying whether the current period contains speech or non-speech content, the system avoids unreliable processing during unsuitable conditions while maintaining adaptability to changing environments.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of echo cancellation in an acoustic system, comprising a first user device and at least one further user device, the method comprising, at the first user device: detecting an audio signal received from the at least one further user device over a communications network; supplying the audio signal when received to an audio signal processing module of the first user device, wherein the audio signal processing module processes the audio signal and outputs a processed audio signal to audio output means of the first user device; and controlling an echo cancellation process for cancelling echo from an audio signal received via audio input means of the first user device based on a loopback signal provided by the processed audio signal and selectively based on the received audio signal when detected.