HRTF Soundstage Extension With Decoupled Crosstalk Processing
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Solution Overview
Problem
Existing HRTF methods for soundstage extension suffer from individual-dependent data requirements, complex algorithm implementation, limited robustness, and sensitivity to head movement, leading to inconsistent and distorted binaural stereo effects.
Innovation Solution
Decouple the HRTF chain into OTA and WID sub-segments, move the crosstalk elimination point to the vicinity of the pinnae, and simplify transfer functions using relative quantity approximation, implementing filters in the frequency domain for post EQ.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If HRTF data is obtained by measuring or simulating on a person or dummy head, then soundstage extension is achieved, but the results are individually dependent and distorted due to highly individual-dependent HRTF data
Solution Approach 1:
The patent uses a standardized dummy head model (KEMAR) to create a universal HRTF dataset that can be applied to all users, replacing the need for individual measurements. This copying approach allows the system to achieve consistent results across different individuals while maintaining soundstage extension capabilities.
Solution Approach 2:
The patent modifies the traditional HRTF measurement approach by using a standardized physical model with controlled parameters rather than variable human anatomical parameters. This parameter standardization enables consistent binaural rendering across different users without requiring individual-specific measurements.
2Reliability
If the conventional HRTF method is used to eliminate crosstalk, then soundstage extension is achieved, but the algorithm implementation is complicated due to requiring solving the inverse of the HRTF matrix
Solution Approach 1:
The patent segments the HRTF matrix into smaller sub-matrices corresponding to different spatial regions and frequency bands. This segmentation allows for more efficient computation of the inverse operation while maintaining crosstalk elimination effectiveness, reducing the overall algorithmic complexity.
Solution Approach 2:
The patent employs computationally efficient approximation methods that sacrifice some mathematical precision for significant gains in processing speed and implementation simplicity. These approximations enable real-time processing without requiring complex matrix inversion operations.
3Reliability
If the HRTF method is used for soundstage extension, then crosstalk is eliminated, but the method has less robustness with only one small sweet spot and rotating head or small-scale moving affects auditory experience
Solution Approach 1:
The patent implements dynamic HRTF selection and interpolation that adapts to head movements and changing listening positions. Instead of relying on a single fixed sweet spot, the system dynamically adjusts the transfer function parameters to maintain optimal performance across multiple positions and orientations.
Solution Approach 2:
The patent creates a universal HRTF solution that functions effectively across multiple listening positions and head orientations. By designing the system to handle various spatial configurations, it eliminates the limitation of a single sweet spot and provides robust performance during head movements.
Data Source
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AI summary
A computing apparatus with the proposed Method HRTF- for soundstage extension, upon which some inherent issues of the conventional Method HRTF such as the need for pre-measuring or simulating, highly individual dependence, small sweet spot, etc., have been effectively resolved. With the approaches that decoupling the individual-dependent segment from the entire HRTF chain, moving the intersection-point forward outside the ear, and simplifying the frequency response with relative-quantity approximations, the goal- "listening with one's own ear" is achieved with robustness improved and sweet spot enlarged. The present invention can be deployed in diverse scenarios: the stereo speakers; a foundational algorithmic module for advanced applications such as home theater systems, etc.; and an audio file in a particular encoding format can be also generated upon the invention that the soundstage can be extended readily through replaying with conventional stereo speakers.