In-Car Echo Cancellation Using Acoustic Region Segmentation
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Solution Overview
Problem
Simultaneously using in-car communication and hands-free talking results in insufficient acoustic echo cancellation, leading to overlapping or echoing of sounds due to the mixing of sound signals between front and rear seats during conversations.
Innovation Solution
An echo cancellation apparatus with multiple adaptive filters and beamformers is employed to effectively cancel acoustic echoes in all acoustic paths, ensuring clear communication by processing signals from microphones and loudspeakers in predefined regions within and outside a vehicle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If in-car communication and hands-free talking are simultaneously used, then communication versatility is improved, but acoustic echo cancellation becomes insufficient leading to sound overlap
Solution Approach 1:
The acoustic space is divided into multiple regions (front row region and rear row region) with microphones and loudspeakers strategically placed in each region. This segmentation allows independent echo cancellation processing for each region, enabling simultaneous in-car communication and hands-free talking without sound overlap between regions.
2Adaptability or versatility
If microphones and loudspeakers are installed in all seats for hands-free talking, then communication coverage is improved, but acoustic echo from all paths becomes difficult to cancel
Solution Approach 1:
Different acoustic processing strategies are applied to different regions. Front row microphones primarily handle hands-free talking with external parties, while rear row microphones handle in-car communication. Each microphone-loudspeaker pair is optimized for its specific region, reducing the overall complexity of echo cancellation while maintaining comprehensive coverage.
Data Source
AI summary
In-car communication and hands-free talking with good sound quality are realized. An echo cancelation apparatus (4) is for use in a vehicle in which microphones (M1, M2) and loudspeakers (S1, S2) are disposed in acoustic regions (100, 200). A loudspeaker (S1) and a microphone (M1) are disposed in a first acoustic region (100), and a loudspeaker (S2) and a microphone (M2) are disposed in a second acoustic region (200). An acoustic signal picked up by the microphone (M1) disposed in the first acoustic region (100) is emitted from the loudspeaker (S2) disposed in the second acoustic region (200). An acoustic signal picked up by the microphone (M2) disposed in the second acoustic region (200) is emitted from the loudspeaker (S1) disposed in the first acoustic region (100). The microphone (M1) is designed to hardly collect a sound emitted from the loudspeaker (S2).