Virtual Sound Source Spatial Spread via HRTF Synthesis
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Solution Overview
Problem
Existing audio signal processing techniques fail to effectively convey the spatial spread of a virtual sound source, limiting the listener's perception to a localized sound image.
Innovation Solution
An audio processing apparatus that generates an audio signal by synthesizing head-related transfer characteristics from multiple points within a target range, allowing for the perception of a virtual sound source's spatial spread by convolving these characteristics into the audio signal, thereby enabling the listener to perceive the sound source's size and position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a head-related transfer characteristic corresponding to a single-point sound source is imparted to an audio signal, then the sound source can be localized at a specific position, but the listener cannot perceive the spatial spread of the sound image
Solution Approach 1:
The patent divides the single-point sound source into multiple discrete sound source points distributed within a target range. Each point is processed with its own head-related transfer function, and the results are synthesized to create a spatially spread sound image that maintains localization precision while adding spatial extent.
Solution Approach 2:
The patent transitions from a zero-dimensional single-point sound source to a multi-dimensional distributed sound source field. By introducing spatial distribution across multiple points in three-dimensional space, the sound image gains spatial spread while maintaining localization through weighted synthesis.
2Adaptability or versatility
If multiple head-related transfer characteristics are synthesized to enable spatial spread perception, then the listener can perceive the sound source size and position, but the processing complexity increases
Solution Approach 1:
The patent pre-calculates and stores head-related transfer functions for multiple discrete sound source points before actual audio processing. This preliminary preparation allows the processing system to simply retrieve and synthesize pre-computed HRTFs during playback, significantly reducing real-time computational complexity.
Solution Approach 2:
The patent uses weighted synthesis where the weights of multiple HRTFs are adjusted based on the desired sound source position and size parameters. By changing these weight parameters dynamically, the system can control the spatial characteristics without recalculating the entire HRTF set, reducing processing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the listener to perceive a virtual sound source as it spatially spreads, allowing for the perception of various sizes and positions of the sound source, enhancing the audio experience by providing a more immersive and realistic sound localization.
Implementation Method 1
imparting to an audio signal a head-related transfer characteristic obtained by synthesis of a plurality of head-related transfer characteristics
Data Source
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AI summary
An audio processing apparatus has a setting processor that sets a size of a virtual sound source; and a signal processor that generates an audio signal by imparting to an audio signal a plurality of head-related transfer characteristics. The plurality of head-related transfer characteristics corresponds to respective points within a range that accords with the size set by the setting processor from among a plurality of points, with each point having a different position relative to a listening point.