Loudspeaker Canceling Beamformer for Acoustic Echo Attenuation
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Solution Overview
Problem
Conventional acoustic echo cancellation techniques and adaptive beamforming systems struggle to effectively attenuate echo signals generated by loudspeakers, especially when they produce high-volume output, leading to distortion that cannot be removed by existing methods.
Innovation Solution
The system determines a loudspeaker canceling beam (LCB) and generates LCB audio data using fixed filter coefficient values based on the microphone array and loudspeaker configuration, which is then subtracted from input audio data to improve echo cancellation, even in the presence of distortion or nonlinearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional acoustic echo cancellation techniques are used, then the system can process audio input, but echo signals from loudspeakers cannot be effectively attenuated
Solution Approach 1:
The patent segments the audio processing by creating a dedicated loudspeaker canceling beam (LCB) that specifically targets and processes echo signals from loudspeaker directions, separating this function from general audio processing to achieve effective echo attenuation
Solution Approach 2:
The patent applies local quality by using fixed filter coefficient values specifically configured for the loudspeaker and microphone array geometry, creating a specialized processing path for echo cancellation that is optimized for specific spatial locations rather than general-purpose processing
2Power
If loudspeakers produce high-volume output, then audio playback quality is improved, but distortion occurs that cannot be removed by existing methods
Solution Approach 1:
The patent applies preliminary action by pre-calculating fixed filter coefficient values based on the known loudspeaker and microphone array configuration before audio playback occurs. This allows the system to prepare the optimal cancellation path in advance, enabling effective distortion removal even when loudspeakers operate at high volumes
Solution Approach 2:
The patent converts the harmful distortion and echo signals generated by high-volume loudspeaker output into beneficial information by using these signals to train and optimize the loudspeaker canceling beam, transforming the problem of distortion into a basis for creating an effective cancellation mechanism
3Object-affected harmful factors
If adaptive beamforming systems are used, then noise filtering is improved, but complexity increases and echo attenuation remains insufficient
Solution Approach 1:
The patent employs a fixed filter coefficient approach rather than complex adaptive algorithms, using a simpler, more computationally efficient method that achieves effective echo cancellation without requiring continuous adaptation or complex processing, thereby reducing system complexity while maintaining performance
Data Source
AI summary
Techniques for improving acoustic echo cancellation to attenuate an echo signal generated by a loudspeaker included in a device are described. A system may determine a loudspeaker canceling beam (LCB) (e.g., fixed beam directed to the loudspeaker) and may use the LCB to generate LCB audio data that corresponds to the echo signal. For example, based on a configuration of the loudspeaker relative to microphone(s) of the device, the system may perform simulation(s) to generate a plurality of filter coefficient values corresponding to the loudspeaker. By subtracting the LCB audio data during acoustic echo cancellation, the system may attenuate the echo signal even when there is distortion or nonlinearity or the like caused by the loudspeaker. In some examples, the system may perform acoustic echo cancellation using the LCB audio data and playback audio data.