Acoustic Feedback Cancellation for Two-Way Conversation
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Solution Overview
Problem
Existing two-way conversation systems fail to effectively remove acoustic noise, including echoes and crosstalk, in confined spaces such as vehicles, leading to poor communication quality.
Innovation Solution
A two-way conversation assisting device and method that employs a configuration of microphones and loudspeakers with integrated acoustic feedback and echo/crosstalk cancellers, using digital signal processing to remove interference signals and update transfer functions in real-time, ensuring clear communication between participants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acoustic echo cancellation systems are implemented with multiple models to cancel speech from both electrical and acoustic transmission paths, then communication quality is improved, but device complexity increases significantly
Solution Approach 1:
The patent divides the acoustic noise cancellation into separate functional modules: acoustic feedback cancellers for each microphone-loudspeaker pair, and echo/crosstalk cancellers for each microphone. Each canceller is independently configured with its own transfer function, allowing the complex overall system to be managed through modular, segmented components that can be processed separately yet work together to achieve comprehensive noise cancellation.
2Reliability
If real-time digital signal processing is used to remove acoustic noise, then communication clarity is improved, but computational requirements and processing time increase
Solution Approach 1:
The system performs preliminary action by continuously updating transfer functions in advance of actual speech transmission. The acoustic feedback cancellers and echo/crosstalk cancellers are pre-configured with transfer functions that model the acoustic paths between microphones and loudspeakers. This preliminary modeling allows the system to rapidly cancel noise in real-time without requiring complex computational processing during active speech transmission, thereby reducing processing time while maintaining communication clarity.
3Adaptability or versatility
If multiple microphones and loudspeakers are deployed in confined spaces, then conversation coverage is improved, but acoustic feedback and crosstalk increase
Solution Approach 1:
The patent implements feedback mechanisms where the output of each microphone is fed back through acoustic feedback cancellers that use transfer functions to model and cancel the acoustic paths. The system continuously monitors and adjusts the cancellation signals based on the actual acoustic environment, creating a closed-loop feedback system that adapts to changes in speaker positions, microphone sensitivity, and acoustic conditions in the confined space, thereby reducing feedback and crosstalk while maintaining broad conversation coverage.
4Ease of manufacture
If acoustic noise cancellation is implemented without additional hardware, then cost is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces mechanical/acoustic solutions with digital signal processing. Instead of using additional physical hardware components like acoustic barriers, directional transducers, or specialized microphone arrays, the system uses software-based acoustic feedback cancellers and echo/crosstalk cancellers that process signals digitally. This substitution of mechanical systems with digital processing reduces manufacturing costs and simplifies hardware requirements, while the precision requirements are managed through algorithmic approaches that adapt to the actual acoustic environment rather than requiring precise physical manufacturing tolerances.
Data Source
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AI summary
A two-way conversation assisting device includes a first microphone that enters a first voice, a first loudspeaker that outputs the first voice, a second microphone that enters a second voice, a second loudspeaker that outputs the second voice, and a first echo and crosstalk canceller. The first echo and crosstalk canceller estimates and calculates, using an input signal into the second loudspeaker, a first interference signal indicative of degrees of a first echo caused when the second voice output from the second loudspeaker enters into the first microphone and first crosstalk caused when the second voice enters into the first microphone, and removes the calculated first interference signal from an output signal of the first microphone.