Audio Reconstruction Using Directional Weighting for Spatial Resolution
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Solution Overview
Problem
Current technologies fail to effectively enhance the perception of a specific direction of origin for audio signals during reproduction, especially in multi-channel setups, due to limitations in microphone directivity patterns and the need for specialized equipment and complex signal processing techniques.
Innovation Solution
The method involves reconstructing audio signals with associated direction parameters to selectively emphasize or attenuate sound from specific directions, using arbitrary spatial weighting functions that can be time and frequency variant, allowing for improved directional perception without requiring hardware changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If narrow directional microphones are used to capture sound from specific directions, then the directional precision is improved, but the cost increases and frequency response degrades
Solution Approach 1:
The patent segments the audio signal processing into multiple channels, each associated with a specific spatial direction. Instead of using one narrow directional microphone, it uses multiple omnidirectional microphones and processes their signals separately in different frequency bands, assigning each to specific spatial directions through filter banks.
Solution Approach 2:
The patent changes the parameter of microphone directivity from narrow directional to omnidirectional, and compensates for the loss of directional precision through signal processing parameters (filter banks, frequency channel assignment, and spatial direction mapping) rather than relying on physical microphone characteristics.
2Ease of manufacture
If omnidirectional microphones with broad directivity patterns are used, then the cost decreases and frequency response improves, but the spatial resolution and directional perception deteriorate
Solution Approach 1:
The patent adds a frequency dimension to the spatial processing. By dividing the frequency spectrum into multiple bands and assigning different spatial directions to different frequency channels, it creates a frequency-spatial mapping that enhances directional perception without requiring narrow directional microphones.
Solution Approach 2:
The patent introduces filter banks and signal processing algorithms as intermediaries between the omnidirectional microphones and the final audio output. These intermediaries process the broad-spectrum signals to extract and emphasize directional information, acting as a bridge between the omnidirectional capture and directional reproduction.
3Area of stationary object
If 5.1 multi-channel loudspeaker systems are used, then the spatial coverage is improved, but the adaptability to different reproduction setups decreases
Solution Approach 1:
The patent creates a universal audio encoding system that can be reproduced on any loudspeaker configuration. The encoded audio data includes spatial direction information that can be adaptively mapped to different loudspeaker setups, making the system compatible with 5.1, 7.1, stereo, or even monaural reproduction without requiring a specific standard configuration.
4Device complexity
If standard two-channel stereo setups are used, then the device complexity is reduced, but the spatial composition reproduction capability deteriorates
Solution Approach 1:
The patent extracts spatial direction information from the multi-channel audio signal and encodes it in a compressed form that can be reproduced on simpler systems. By separating and encoding the directional characteristics independently, it enables two-channel systems to reproduce spatial composition that was originally captured in multi-channel formats.
Data Source
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AI summary
An audio signal having at least one audio channel and associated direction parameters indicating a direction of origin of a portion of the audio channel with respect to a recording position is reconstructed to derive a reconstructed audio signal. A desired direction of origin with respect to the recording position is selected. The portion of the audio channel is modified for deriving a reconstructed portion of the reconstructed audio signal, wherein the modifying comprises increasing an intensity of the portion of the audio channel having direction parameters indicating a direction of origin close to the desired direction of origin with respect to another portion of the audio channel having direction parameters indicating a direction of origin further away from the desired direction of origin.