Vehicle Microphone Array Asymmetry for Noise Suppression
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Solution Overview
Problem
Existing noise suppression techniques using microphone arrays in vehicles face challenges when dealing with multiple noise sources in the lateral direction, as equal distances from the microphones to noise sources and the speaker of interest complicate noise suppression, making efficient noise reduction impossible.
Innovation Solution
A speech processing system with a microphone array comprising multiple microphones arranged such that the difference in distances from the microphones to the speaker of interest differs from the difference in distances to the noise sources, allowing for effective noise suppression by outputting mixture signals that vary in arrival time and volume, which are then processed by a noise suppressor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If microphones are arranged in a lateral direction with equal distances to the speaker and noise sources, then the microphone array can capture sound from multiple directions, but the noise suppression processing becomes complicated and inefficient
Solution Approach 1:
The patent applies asymmetry by arranging microphones at different distances from the speaker and noise sources. Specifically, the microphone array is configured such that at least one microphone has a different distance relationship to the speaker compared to the noise sources, creating an asymmetric geometric configuration. This asymmetry allows the noise suppression processor to distinguish between speech and noise signals more easily, simplifying the processing while maintaining effective noise reduction capability.
2Device complexity
If microphones are arranged to have equal distances to multiple noise sources, then the array structure is simplified, but efficient noise suppression for multiple noise sources becomes impossible
Solution Approach 1:
The patent applies local quality by creating different distance relationships for different microphone-noise source pairs. The microphone array is configured so that each microphone has a unique distance relationship to the noise sources and the speaker, rather than maintaining uniform distances. This local differentiation in distance metrics enables the noise suppression processor to effectively separate and suppress multiple noise sources while preserving the speaker's speech, thereby achieving high noise suppression efficiency without excessive structural complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This arrangement enables efficient noise suppression for multiple noise sources by distinguishing speech and noise signals based on their differing arrival times and volumes, improving the overall noise reduction in vehicle environments.
Implementation Method 1
a microphone array 101 including a plurality of microphones 2004 and 2005... each of which inputs a sound mixture including speech of a speaker of interest and noise from a noise source region
Data Source
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AI summary
A system of this invention is directed to a speech processing system that efficiently performs noise suppression processing for a plurality of noise sources spreading in a lateral direction with respect to a speaker of interest. A speech processing system comprises: at least one hardware processor configured to implement: a linear microphone array (201, 701) comprising a plurality of microphones (211, 212), arranged on a straight line, each of which inputs speech of a speaker (220) of interest and noise from a noise source region (310, 320) comprising a plurality of noise sources, and outputs a mixture signal comprising said speech and said noise; and a noise suppressor (430) that suppresses said noise based on said mixture signals, wherein a direction of arranging the plurality of microphones (211, 212) in said linear microphone array (210, 701) is determined such that said straight line is perpendicular to a longitudinal axis of said noise source region (310, 320), and a distance, between said linear microphone array (201, 701) and said noise source region (310, 320), and a tilt of a placement plane of said microphone array (201, 701) are adjusted so as to decrease differences between respective distances from each of noise sources in said noise source region (310, 320) to the plurality of microphones (211, 212) in said linear microphone array (201, 701