Acoustic Signal Cancellation Using Synchronized Reference Signals
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Solution Overview
Problem
Existing acoustic echo cancellation and noise reduction mechanisms in user devices fail to effectively eliminate the echo of external audio signals, such as TV broadcasts, from being captured by microphones, leading to a poor user experience during shared content consumption.
Innovation Solution
A computerized acoustic signal cancellation system that synchronizes a reference signal with a captured acoustic signal to cancel out the external audio signal, using processing circuitry to generate a synchronized reference signal and apply it to the captured signal, thereby reducing the echo and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If acoustic echo cancellation is performed using existing mechanisms, then echo from the user device speaker is reduced, but echo from external audio devices (TV, radio) is not eliminated
Solution Approach 1:
The patent introduces a reference signal from an external audio device (TV, radio) as an intermediary to enable cancellation of external audio echo. The reference signal serves as a mediator between the external audio source and the acoustic echo canceller, allowing the system to identify and remove external audio echo that conventional mechanisms cannot detect
Solution Approach 2:
The patent segments the echo cancellation problem into two distinct components: internal device echo (handled by conventional AEC) and external audio echo (handled by the new reference signal mechanism). This segmentation allows each component to be addressed with appropriate technical solutions
2Object-affected harmful factors
If noise reduction mechanisms are applied to suppress background noise, then stationary noise is reduced, but external audio signals are not distinguished and removed
Solution Approach 1:
The patent applies a metaphorical 'color change' by giving external audio signals a unique identifier through the reference signal. This allows the system to distinguish external audio content from ordinary background noise, enabling selective cancellation of only the external audio echo while preserving other background sounds
3Object-affected harmful factors
If reference signal synchronization is implemented, then external audio echo cancellation is achieved, but system complexity increases
Solution Approach 1:
The system employs self-service mechanisms where the acoustic echo canceller automatically processes the reference signal to generate the anti-echo signal, and the synchronization is maintained through inherent system operations rather than requiring complex external control mechanisms
Data Source
AI summary
An acoustic signal cancellation system is configured to perform: (a) provide a user device, associated with the system, and an audio capture device. (b) receive at system a captured signal indicative of a captured acoustic signal. It's received at capture device, and comprises a second acoustic signal generated by a second device, external to user device. (c) receive, from external source, a reference signal, indicative of a content included in the second signal. (d) in a case that a content of reference signal and the content in second signal are not time-synchronized, generate a synchronized reference signal, based on reference signal. Content of synchronized reference signal and second signal content are time-synchronized. (e) perform acoustic signal cancelling of that portion of captured signal which corresponds to second signal, based on reference signal. Generate reduced signal. This facilitates output of reduced signal to third device.