Microphone Array Beamforming for Vehicular Wind Noise Reduction
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Solution Overview
Problem
Handsfree systems, particularly in vehicular applications, face challenges in signal-to-noise ratio (SNR) deterioration due to distance between microphones and speakers, high ambient noise, and wind noise, which traditional beamforming methods struggle to address effectively, especially in reverberant environments and with non-stationary signals.
Innovation Solution
A system that decomposes microphone signals into frequency sub-band signals, determines time-dependent measures, and uses a criterion function to detect uncorrelated noise, such as wind noise, and modifies the beamformer output signal to reduce noise, enhancing the signal-to-noise ratio without requiring large windshields or impractical numbers of microphones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If large windshields are used to reduce wind noise, then wind noise reduction is achieved, but microphone size increases
Solution Approach 1:
The patent replaces the mechanical windshield approach with an electronic detection and reduction system. By analyzing statistical properties of microphone signals and detecting uncorrelated noise through signal level variations, the system achieves wind noise reduction without requiring large physical windshields, thereby maintaining compact microphone dimensions.
2Measurement precision
If an impractical number of microphones are used, then significant SNR improvement with DSBF is achieved, but system complexity and cost increase
Solution Approach 1:
The patent introduces statistical analysis of microphone signal levels as an intermediary mechanism. Instead of relying solely on increasing the number of microphones for SNR improvement, the system uses statistical detection of uncorrelated noise to enhance the effectiveness of existing microphone arrays, achieving better SNR with fewer microphones.
Data Source
AI summary
A system for detecting noise in a signal received by a microphone array and a method for detecting noise in a signal received by a microphone array is disclosed. The system also provides for the reduction of noise in a signal received by a microphone array and a method for reducing noise in a signal received by a microphone array. The signal to noise ratio in handsfree systems may be improved, particularly in handsfree systems present in a vehicular environment.