Multi-Microphone Wind Noise Detection via Phase Angle Differences
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-microphone systems face challenges in reliably detecting wind noise due to overlapping spectral or temporal content with desired signals, particularly in portable electronic equipment, where wind noise is annoying and degrades speech intelligibility and sound recording fidelity.
Innovation Solution
A multi-microphone system that determines phase angle differences between first and second microphone signals over time using a signal processor assembly, which filters and averages these differences to detect wind noise based on predetermined criteria, allowing for effective wind noise detection and cancellation in specific frequency sub-bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wind noise is detected using amplitude features in microphone signals, then wind noise can be identified, but reliable detection becomes difficult due to overlapping spectral or temporal content with desired signals
Solution Approach 1:
The patent introduces phase angle differences as an intermediary parameter to detect wind noise. Instead of directly analyzing amplitude features that overlap with desired signals, the system uses phase relationships between multiple microphone signals as a mediator that uniquely characterizes wind noise without overlapping with speech or music signals.
Solution Approach 2:
The patent changes the detection parameter from amplitude-based features to phase angle difference features. By transforming the detection domain from amplitude to phase, the system finds a parameter space where wind noise exhibits distinctive characteristics that do not overlap with desired audio signals, thereby improving detection reliability.
2Object-affected harmful factors
If a wind screen is placed over the microphone inlet ports to reduce turbulence, then wind noise is reduced, but the solution becomes impractical for portable electronic equipment due to size and appearance constraints
Solution Approach 1:
The patent replaces the mechanical wind screen solution with a signal processing approach. Instead of using physical barriers to reduce turbulence, the system uses electronic signal processing to detect and mitigate wind noise, thereby eliminating the need for bulky mechanical components in portable devices.
Solution Approach 2:
The patent extracts the wind noise component from the microphone signals through phase-based detection and separates it from the desired audio signals. By identifying and isolating the wind noise through phase angle analysis, the system can remove or attenuate only the harmful wind noise components while preserving the desired speech and music signals.
3Reliability
If phase angle differences between multiple microphone signals are used to detect wind noise, then reliable detection is achieved, but the system complexity increases
Solution Approach 1:
The patent segments the audio spectrum into different frequency sub-bands and performs phase angle difference analysis separately in each sub-band. This segmentation allows the system to focus computational resources on specific frequency ranges where wind noise is most prominent, reducing overall computational complexity while maintaining detection reliability.
Data Source
AI summary
The present invention relates to a multi-microphone system and method adapted to determine phase angle differences between a first microphone and a second microphone signal to detect presence of wind noise.