Common Gain Coefficient for Spatial Stability in Audio Processing
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Solution Overview
Problem
Stereo and multichannel audio configurations often lose spatial information due to noise suppression processes, resulting in a mono output signal that lacks spatial stability.
Innovation Solution
A system and method that estimates background noise for each audio signal, calculates gain coefficients using an automatic gain controller, noise suppressor, and echo canceller, and selects a common gain coefficient to apply to both signals, minimizing audio signal modification and maintaining spatial stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If noise suppression processing is applied to improve noise performance, then noise is reduced, but spatial information is lost resulting in mono output signal
Solution Approach 1:
The patent segments the audio processing by separating noise suppression operations from spatial processing operations. Different gain coefficients are calculated for different channels, allowing noise suppression to be applied selectively without collapsing the spatial structure into a single mono signal.
Solution Approach 2:
The patent applies local quality by using channel-specific gain coefficients rather than a global gain coefficient. Each audio channel receives tailored noise suppression processing based on its own characteristics, preserving the spatial relationships between channels while still suppressing noise locally in each channel.
2Object-affected harmful factors
If different gain coefficients are applied to different audio signals to optimize noise suppression, then noise performance improves, but spatial stability deteriorates due to inconsistent signal modification
Solution Approach 1:
The patent uses feedback by monitoring the spatial characteristics of the audio signals and adjusting gain coefficients to maintain spatial stability. The system continuously evaluates the spatial relationships and modifies processing parameters to preserve the intended spatial image while still achieving noise suppression.
Solution Approach 2:
The patent dynamically changes processing parameters by selecting from multiple possible gain coefficients based on current spatial stability requirements. When spatial stability is compromised, the system adjusts the gain coefficient selection criteria to restore stability, balancing noise suppression with spatial preservation.
3Stability of the object's composition
If a common gain coefficient is applied to multiple audio signals, then spatial stability is maintained, but noise suppression effectiveness is reduced
Solution Approach 1:
The patent implements dynamic gain coefficient selection where the system transitions between using individual channel gain coefficients and common gain coefficients based on real-time spatial stability assessment. This dynamic approach allows the system to optimize noise suppression when spatial stability is maintained while preserving spatial stability when needed.
Solution Approach 2:
The patent creates a universal gain coefficient selection mechanism that can adapt to different operational conditions. The same gain coefficient selection apparatus serves dual functions: optimizing noise suppression when channels are stable and maintaining spatial stability when channels diverge, making the system versatile across different acoustic scenarios.
Data Source
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AI summary
In a system and method for maintaining the spatial stability of a sound field a background noise estimate may be estimated for each of a first signal and a second signal. A first gain coefficient may be calculated responsive to the first audio signal and the background noise estimate of the first audio signal. A second gain coefficient may be calculated responsive to the second signal and the background noise estimate of the second signal. The gain coefficients may be calculated using one or more gain coefficient calculators. A common gain coefficient may be selected from one of the first gain coefficient and the second gain coefficient. The selected common gain coefficient may be one that results in a least amount of audio signal modification and may be applied to each of the first signal and the second signal.