Wind Detection and Suppression for Audio Pickup Systems

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Solution Overview

Problem

Wind noise interference significantly affects sound pickup systems, even at low levels, by obscuring desired voice signals, and existing solutions fail to effectively distinguish wind noise from voice and noise, leading to false alarms and degradation in speech quality.

Innovation Solution

A dual-channel wind detection and suppression system that uses a combination of spectral slope, ratio, and coherence features to accurately identify wind noise, employing a wind detector to continuously estimate wind levels and activate a wind suppressor, thereby reducing wind noise impact while minimizing false alarms and preserving speech quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If wind suppression is applied continuously, then wind noise is reduced, but speech quality deteriorates due to false alarms

Engineering Contradiction:
Improvewind noise interferenceVSAvoidfalse alarm rate
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The system dynamically adjusts the wind suppression activation based on real-time wind level estimates. The wind detector continuously monitors wind conditions and activates suppression only when wind levels exceed a threshold, rather than applying continuous suppression. This dynamic activation reduces false alarms while maintaining wind noise reduction effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of wind suppression based on detected wind levels. When wind is detected, suppression parameters are adjusted to activate; when wind subsides, parameters return to normal. This parameter-based control allows selective application of suppression only when needed, reducing false alarms.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If mechanical shielding is added to reduce wind noise, then wind noise is reduced, but device complexity increases

Engineering Contradiction:
Improvewind noise interferenceVSAvoidsystem complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system replaces mechanical wind shielding solutions (such as physical barriers or acoustic enclosures) with an electronic/digital wind detection and suppression system. The wind detector and processing unit analyze audio signals to identify and suppress wind noise components, achieving wind noise reduction without adding complex mechanical structures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If aggressive wind suppression is applied, then wind noise is reduced, but desired voice signals are also attenuated

Engineering Contradiction:
Improvewind noise interferenceVSAvoidvoice signal quality
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The system applies partial wind suppression by activating it only when wind levels exceed a determined threshold, rather than applying full suppression continuously. The suppression strength is modulated based on the detected wind level, applying just enough suppression to reduce wind noise while preserving voice signal quality when wind is not present.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The wind detector provides continuous feedback about wind levels to the suppression system. This feedback loop allows the system to adjust suppression intensity based on actual wind conditions, reducing suppression when wind is low to preserve voice quality and increasing suppression when wind is strong to reduce noise effectively.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2673956B1System and method for wind detection and suppression
Publication Date: 2019.04.24 DOLBY INTERNATIONAL AB
  • EP2673956B1 patent drawingFigure 1
  • EP2673956B1 patent drawingFigure 2A~2B
  • EP2673956B1 patent drawingFigure 3A

AI summary

In one embodiment, a pickup system includes a wind detector and a wind suppressor. The wind detector has a plurality of analyzers each configured to analyze first and second input signals, and a combiner configured to combine outputs of the plurality of analyzers and issue, based on the combined outputs, a wind level indication signal indicative of wind activity. The analyzers can be selected from a group of analyzers including a spectral slope analyzer, a ratio analyzer, a coherence analyzer, a phase variance analyzer and the like. The wind suppressor has a ratio calculator configured to generate a ratio of the first and second input signals, and a mixer configured to select one of the first or second input signals and to apply to the selected input signal one of first or second panning coefficients based on the wind level indication signal and on the ratio.