Microphone Array Source Localization for Compact Broadband Speech Capture
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Solution Overview
Problem
Conventional microphone arrays are unsuitable for hands-free or handheld speech acquisition devices due to their large and bulky size, which is required to effectively handle broadband speech applications with wide bandwidths, leading to ineffective suppression of ambient noise.
Innovation Solution
A microphone array system comprising an array of sound sensors in an arbitrary configuration, a sound source localization unit, an adaptive beamforming unit, and a noise reduction unit, which estimates the spatial location of the target sound signal and steers the directivity pattern to enhance the target sound while suppressing ambient noise using adaptive beamforming and noise reduction algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional microphone arrays are used for broadband speech applications, then ambient noise suppression is improved, but device size becomes large and bulky
Solution Approach 1:
The patent divides the broadband frequency spectrum into multiple narrowband frequency channels. Each channel is processed independently by separate beamforming filters, allowing the system to achieve effective noise suppression across the entire broadband spectrum using smaller, specialized narrowband filters rather than requiring a single large broadband filter array.
Solution Approach 2:
The patent transforms the broadband signal processing problem into multiple narrowband signal processing problems by applying frequency domain decomposition. This parameter change allows the use of narrowband beamforming techniques that require smaller array configurations while maintaining effective noise suppression performance across the full speech frequency range.
2Adaptability or versatility
If array size is increased to achieve broadband response, then frequency coverage is improved, but portability for handheld devices deteriorates
Solution Approach 1:
The patent segments the broadband frequency spectrum into multiple narrowband channels, each handled by dedicated beamforming filters. This segmentation enables comprehensive frequency coverage across the entire speech band while using compact array configurations suitable for handheld devices, avoiding the need for large physical arrays.
Solution Approach 2:
The patent transitions from spatial domain processing to frequency domain processing by decomposing the broadband signal into multiple narrowband frequency channels. This dimensional transformation allows independent optimization of each frequency channel with appropriate beamforming filters, achieving broad frequency coverage without increasing physical array size.
3Device complexity
If narrowband techniques are used in conventional microphone arrays, then implementation complexity is reduced, but broadband speech application performance deteriorates
Solution Approach 1:
The patent segments broadband speech processing into multiple narrowband frequency channels. Each channel uses relatively simple narrowband beamforming filters, keeping individual filter complexity low. The combination of multiple simple narrowband filters achieves effective broadband speech performance through frequency domain decomposition and independent channel processing.
Data Source
AI summary
A method and system for enhancing a target sound signal from multiple sound signals is provided. An array of an arbitrary number of sound sensors positioned in an arbitrary configuration receives the sound signals from multiple disparate sources. The sound signals comprise the target sound signal from a target sound source, and ambient noise signals. A sound source localization unit, an adaptive beamforming unit, and a noise reduction unit are in operative communication with the array of sound sensors. The sound source localization unit estimates a spatial location of the target sound signal from the received sound signals. The adaptive beamforming unit performs adaptive beamforming by steering a directivity pattern of the array of sound sensors in a direction of the spatial location of the target sound signal, thereby enhancing the target sound signal and partially suppressing the ambient noise signals, which are further suppressed by the noise reduction unit.