Tri-State Voice Switching for Echo Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Acoustic echo cancellation in two-way voice communication systems, particularly on personal computers, is hindered by inaccurate or erratic timestamps, leading to misalignment of microphone and speaker signals, which causes ineffective echo removal.
Innovation Solution
Implementing tri-state voice switching with voluntary and forced transition conditions to smoothly switch between active voice channels, ensuring continuous communication without losing initial syllables or words, and using quality checks to determine when to switch from acoustic echo cancellation to tri-state voice switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If acoustic echo cancellation is used to remove echo from speaker phone in two-way communication systems, then echo reduction is improved, but the system fails when timestamps are inaccurate or erratic causing misalignment of microphone and speaker signals
Solution Approach 1:
The system dynamically switches between full-duplex mode with acoustic echo cancellation and half-duplex mode with voice switching based on detected communication quality. When timestamp misalignment is detected indicating poor communication quality, the system transitions from AEC to voice switching to maintain reliable operation.
Solution Approach 2:
The system continuously monitors communication quality metrics including timestamp accuracy and signal alignment. Based on this feedback, it automatically adjusts the operating mode between full-duplex and half-duplex to optimize echo reduction performance under varying conditions.
2Object-affected harmful factors
If voice switching is used to reduce acoustic echo by selectively turning on/off communication channels, then echo reduction is achieved, but communication becomes half-duplex causing loss of initial syllables or words during channel switching
Solution Approach 1:
The system dynamically adjusts the switching behavior based on detected voice activity and communication state. By monitoring the transition conditions and using tri-state transitions through a bi-directional state, the system minimizes information loss during mode switching while maintaining effective echo reduction.
3Reliability
If tri-state voice switching with voluntary and forced transition conditions is implemented, then smooth channel switching is achieved preventing loss of initial syllables, but device complexity increases
Solution Approach 1:
The voice switching mechanism is segmented into distinct states (full-duplex, half-duplex, bi-directional) with clearly defined transition conditions. This segmentation simplifies the control logic by breaking down the complex switching behavior into manageable state transitions based on voice activity detection and communication quality metrics.
Data Source
AI summary
A voice communication end device performs quality checks to determine whether acoustic echo cancellation would be ineffective, such as due to noise or clock drift or discontinuities between incoming and outgoing voice channels. In the case where echo cancellation would prove ineffective, the device falls back on a tri-state voice switching operation that includes a bi-direction state in which both channels are on in full duplex operation, which provides a smoother transition switching between active channels. The tri-state voice switching supports both voluntary transitions where the active user voluntarily stops to yield the active channel, and forced transitions where the active user is forcedly interrupted by the other user speaking more loudly.