Sound Field Spatial Stabilizer for Noise-Resistant Audio

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Solution Overview

Problem

Existing sound field processing systems using stereo and multichannel microphone configurations often lose spatial information due to noise suppression processes, resulting in a mono output signal that lacks spatial stability and can introduce audible distortions.

Innovation Solution

The system calculates balance gains for each microphone signal to maintain spatial stability by adjusting and mixing signals, using echo cancellation, noise reduction, and background noise estimation techniques, while limiting differences in signal values to mitigate distortions and apply signal gains effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If noise suppression processes are applied to improve noise performance, then noise reduction is achieved, but spatial information is lost and spatial stability deteriorates

Engineering Contradiction:
ImprovenoiseVSAvoidspatial information
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The patent segments the noise suppression process into separate channels for left and right microphones, applying independent signal processing to each channel. This allows noise reduction while preserving the spatial relationship between channels by treating them as distinct entities rather than combining them into a mono signal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different processing characteristics to different microphone channels based on their individual spatial characteristics. By calculating separate balance gains and signal values for each channel, the system maintains local spatial quality while achieving overall noise suppression.

Inventive Principle:
Principle #3Local quality

2Reliability

If signal gains are applied to improve signal characteristics, then audible distortions are reduced, but spatial stability may be compromised without proper balancing

Engineering Contradiction:
Improveaudible distortionsVSAvoidspatial stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback mechanism by calculating balance gains based on the spatial relationship between microphone signals and using these gains to adjust signal levels. The system continuously monitors and adjusts signal values to maintain spatial stability while improving signal characteristics.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts signal processing parameters including balance gains and signal values based on the spatial configuration of microphones and the characteristics of received signals. These parameter changes allow the system to maintain spatial stability while optimizing signal quality.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2760021B1Sound field spatial stabilizer
Publication Date: 2018.01.17 ONTARIO INC
  • EP2760021B1 patent drawingFigure 1
  • EP2760021B1 patent drawingFigure 2
  • EP2760021B1 patent drawingFigure 3

AI summary

In a system and method for maintaining the spatial stability of a sound field a balance gain may be calculated for two or more microphone signals. The balance gain may be associated with a spatial image in the sound field. Signal values may be calculated for each of the microphone. The signal values may be signal estimates or signal gains calculated to improve a characteristic of the microphone signals. The differences between the signal values associated with each microphone signal may be limited although some difference between signal values may be allowable. One or more microphone signals are adjusted responsive to the two or more balance gains and the signal gains to maintain the spatial stability of the sound field. The adjustments of one or more microphone signals may include mixing of two or more microphone. The signal gains are applied to the two or more microphone signals.