Spatially Extended Sound Reproduction via Listener-Based Projection
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Solution Overview
Problem
Existing audio reproduction methods struggle to accurately represent spatially extended sound sources, such as musical instruments or ambient sounds, due to their reliance on point sources, which fail to capture the true spatial extent and often distort the sound's timbre or require numerous decorrelated signals, leading to artifacts and position dependency.
Innovation Solution
A method and apparatus that calculate a projection of a spatially extended sound source's two- or three-dimensional hull onto a projection plane, using a listener's position to determine sound source positions, allowing for efficient rendering of the sound source as multiple decorrelated signals associated with a single spatially extended sound source, reducing the number of required point sources and minimizing distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If point sources are used to reproduce sound, then the reproduction setup is simple, but the spatial extent and realism of the sound source cannot be accurately captured
Solution Approach 1:
The spatially extended sound source is segmented into multiple point sources distributed across its surface or volume. Each point source contributes to the overall sound field, collectively representing the extended nature of the original source while maintaining computational tractability.
Solution Approach 2:
Different regions of the sound source are assigned different acoustic characteristics through localized point sources. Each point source captures local emission properties, allowing the reproduction system to preserve spatially varying features such as directionality and timbre across the extended source.
2Measurement precision
If numerous decorrelated signals are used to represent spatially extended sound sources, then the spatial extent is better captured, but artifacts and position dependency increase
Solution Approach 1:
Instead of using numerous independently decorrelated signals, the invention uses multiple point sources that are spatially distributed but acoustically correlated through their geometric relationship to the listener. This copying approach replicates the physical spatial configuration rather than relying on signal processing artifacts.
Solution Approach 2:
Rather than decorrelating signals to create spatial extent, the invention inverts the approach by using spatially distributed point sources whose natural geometric relationships create the perceived spatial extent without requiring signal decorrelation. This eliminates the artifacts associated with decorrelation techniques.
3Measurement precision
If multiple point sources are used to represent spatially extended sound sources, then the spatial extent is better captured, but the computational overhead increases
Solution Approach 1:
The invention uses a sufficient number of point sources to accurately represent the spatial extent without employing excessive point sources. The number of point sources is optimized to provide adequate spatial representation while maintaining computational efficiency, avoiding both under-sampling and over-complexity.
Data Source
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AI summary
Apparatus for reproducing a spatially extended sound source having a defined position and geometry in a space, the apparatus comprises an interface (100) for receiving a listener position; a projector (120) for calculating a projection of a two-dimensional or three-dimensional hull associated with the spatially extended sound source onto a projection plane using the listener position, information on the geometry of the spatially extended sound source, and information on the position of the spatially extended sound source; a sound position calculator (140) for calculating positions of at least two sound sources for the spatially extended sound source using the projection plane; and a renderer (160) for rendering the at least two sound sources at the positions to obtain a reproduction of the spatially extended sound source having two or more output signals, wherein the renderer (160) is configured to use different sound signals for the different positions, wherein the different sound signals are associated with the spatially extended sound source.