Stereo to 5.1 Audio Signal Transformation via Frequency Domain Separation
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Solution Overview
Problem
Existing methods for transforming stereophonic sound signals into 5.1 sound signals fail to provide effective sound discrimination between different loudspeakers, leading to issues like pumping effects and instability, which affect the listener's experience and the integrity of the original sound effect.
Innovation Solution
The method involves transforming stereophonic sound signals into the frequency domain to identify in-phase and out-of-phase components, using specific filters to separate and broadcast these components to distinct loudspeakers, thereby avoiding pumping effects and ensuring accurate sound discrimination without modifying the original sound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If compressors with long response times are used to separate monophonic components in temporal domain, then sound signal processing is achieved, but pumping effects occur causing sudden intensity variations
Solution Approach 1:
The patent transforms the sound processing from temporal domain to frequency domain, changing the fundamental parameter domain. This allows separation of monophonic and stereophonic components through frequency analysis rather than temporal compression, eliminating the pumping effect while maintaining sound discrimination.
Solution Approach 2:
The patent replaces the mechanical/temporal compression system with a frequency-domain filtering system. Instead of using compressors that operate in temporal domain with inherent response time delays, the invention uses spectral analysis and frequency domain operations to achieve component separation without temporal artifacts.
2Measurement precision
If monophonic components are strongly attenuated in center channel, then sound discrimination improves, but inertia causes sound emptiness sensations
Solution Approach 1:
The patent changes the processing domain from temporal to frequency, allowing precise control of monophonic component attenuation across different frequency bands. This prevents the inertial delay in attenuation/highlighting transitions, maintaining continuous and natural sound perception without emptiness sensations.
3Device complexity
If same electrical sound signal is broadcast on two rear loudspeakers, then equipment complexity is reduced, but sound discrimination between rear channels is poor
Solution Approach 1:
The patent applies segmentation by separating the rear channel signals into distinct left and right components through frequency domain processing. Instead of broadcasting the same signal to both rear loudspeakers, the invention extracts and assigns specific frequency components to each rear channel, achieving sound discrimination without significantly increasing system complexity.
4Ease of operation
If stereophonic components are transformed to 5.1 signals, then auditory comfort is improved, but original sound effect integrity is compromised
Solution Approach 1:
The patent uses frequency domain transformation to separate sound components while preserving the original temporal relationships and characteristics. By working in the frequency domain and using inverse transformation, the method maintains the integrity of the original sound effect while achieving 5.1 channel distribution for improved auditory comfort.
Data Source
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AI summary
The invention essentially relates to a method of producing more than two different electric time sound signals (C(t), GF(t), DF(t), GA(t), DA(t)) from two initial electric time signals (Gl(t), Dl(t)). The inventive method comprises the following steps consisting in: in the frequency domain, producing a central electric frequency sound signal (C(v)) from the in-phase frequency components of the initial signals; and producing two front signals (GF(t), DF(t)) by subtracting the central signal (C(t)) from the initial signals (Gl(t), Dl(t)). In addition, two rear signals (GA(t), DA(t)) can be produced from the out-of-phase frequency components of the initial signals. In this way, the method can be used to transform a stereophonic signal into a type 5.1 signal comprising five different sound signals.