Microphone Coherence Filtering for Wind Noise Reduction
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Solution Overview
Problem
Existing audio systems struggle to effectively reduce wind noise in signals generated by microphones, particularly in environments with air turbulence, which degrades audio quality.
Innovation Solution
An audio system processes signals from multiple microphones to determine coherence between them, applying a filter based on spectral gain and a band-pass filter to reduce wind noise by filtering out uncorrelated noise components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wind noise reduction filtering is applied to microphone signals, then audio quality is improved, but signal processing complexity increases
Solution Approach 1:
The patent replaces complex mechanical wind noise reduction mechanisms with a computational approach using coherence-based spectral filtering. Instead of using physical barriers or mechanical filters, the system uses digital signal processing to analyze the coherence between multiple microphone signals and selectively filter wind noise frequencies, thereby reducing hardware complexity while maintaining audio quality.
Solution Approach 2:
The patent changes the parameter of noise filtering from fixed-frequency filtering to dynamic coherence-based filtering. By calculating the coherence between signals from multiple microphones across different frequency bins and time frames, the system adaptively identifies and filters wind noise components, improving audio quality without requiring overly complex fixed-structure filters.
2Object-affected harmful factors
If coherence-based filtering is used to reduce wind noise, then wind noise reduction effectiveness is improved, but computational requirements increase
Solution Approach 1:
The patent applies partial coherence-based filtering by selectively processing only those frequency bins and time frames where wind noise is detected through coherence analysis. Instead of uniformly processing all signal components, the system identifies regions with high coherence indicative of wind noise and applies filtering only to those specific portions, reducing overall computational energy consumption while maintaining effective wind noise reduction.
3Measurement precision
If multiple microphones are used for coherence analysis, then wind noise filtering accuracy is improved, but device complexity increases
Solution Approach 1:
The patent introduces coherence as an intermediary metric to bridge the signals from multiple microphones. By calculating the coherence between microphone signals across frequency bins and time frames, the system creates a unified measure of correlation that simplifies the comparison and filtering process, thereby improving filtering accuracy without proportionally increasing device complexity.
Data Source
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AI summary
The disclosure is generally directed to a system for reducing wind noise. A system includes one or more processors coupled to a non-transitory computer-readable storage medium having instructions encoded thereon that, when executed by the one or more processors, cause the one or more processors to obtain signals respectively generated from two or more microphones during a time period, the signals representing acoustic energy detected by the two or more microphones during the time period, determine a coherence between the signals, and determine a filter based on the coherence. The filter is configured to reduce wind noise in one or more of the signals.