Spatial Sound Capture Using VBAP Beamformer Optimization
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Solution Overview
Problem
Current systems fail to effectively capture and reproduce the complex acoustic environments of crowded events, such as concerts or sporting events, with minimal delay, and accurately transmit the spatial sound to end users, often resulting in a loss of immersive experience due to imperfect beamformer shapes and noise amplification.
Innovation Solution
A processor-implemented method and system that captures input signals using multiple sensors, applies short-time Fourier transforms, decomposes signals into directional and diffuse components, optimizes beamformer weights using Vector Based Amplitude Panning, and distributes these components to output devices for accurate spatial sound reproduction, employing techniques like Tikhonov regularization to mitigate noise amplification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If beamforming is used to capture spatial sound in crowded acoustic environments, then directional sound can be extracted, but the beamformer shapes are imperfect and noise is amplified
Solution Approach 1:
The sound field is decomposed into directional and diffuse components separately. The directional component is extracted using DOA estimation and VBAP, while the diffuse component is captured using optimized beamformers with Tikhonov regularization to suppress noise amplification. This segmentation allows each component to be processed with appropriate techniques.
Solution Approach 2:
Tikhonov regularization is applied to modify the beamformer weight calculation by adding a regularization term to the cost function. This parameter change stabilizes the inverse problem and prevents noise amplification while maintaining directional capture capability.
2Adaptability or versatility
If traditional surround sound systems are used, then spatial sound can be reproduced, but the immersive experience is lost due to inability to capture crowded chaotic acoustic environments
Solution Approach 1:
The system transitions from traditional 5.1 surround sound to spatial audio by adding the vertical dimension and precise directional information. Multiple sensors capture sound from different spatial positions, and the processed directional and diffuse components are distributed to create a three-dimensional sound field that preserves the immersive experience of crowded environments.
Solution Approach 2:
The patent introduces an intermediate processing stage that decomposes the captured sound field into directional and diffuse components. This intermediary representation allows for separate optimization and processing of each component before final reproduction, enabling accurate spatial sound transmission.
3Loss of time
If minimal delay is used for sound transmission, then real-time broadcasting is achieved, but signal processing quality may be compromised
Solution Approach 1:
The system performs preliminary processing of the sound field by decomposing it into directional and diffuse components before transmission. This pre-processing allows for efficient encoding and minimal delay during transmission, while the quality is maintained through the robustness of the decomposition approach and optimized beamforming.
Data Source
AI summary
A processor-implemented method for capturing and reproducing spatial sound. The method includes: capturing a plurality of input signals using a plurality of sensors within a sound field; subjecting each input signal to a short-time Fourier transform to transform each signal into a transformed signal in the time-frequency domain; decomposing each of the transformed signals into a directional component and a diffuse component; optimizing beamformer weights using vector based amplitude panning to determine an optimal directivity pattern for the diffuse component of each transformed signal; constructing a set of diffuse sound channels using the diffuse components of the transformed signals and the optimized beamformer weights; constructing a set of directional sound channels using the directional components of the transformed signals; and reproducing the sound field by distributing the directional and diffuse sound channels to a plurality of output devices.