Acoustic Crosstalk Filter Interpolation for Six-DOF Head Movement

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Solution Overview

Problem

Conventional crosstalk cancellation techniques struggle to effectively handle user head movements in three-dimensional space, leading to degraded performance and increased interference due to high computational demands for six-degrees of freedom.

Innovation Solution

A computer-implemented method determines a user's position and orientation, identifies a subset of nearest points in a dimensional map, assigns weights to transfer functions based on distance, and combines these functions to generate crosstalk cancellation filters for multiple speakers, reducing computational costs while improving crosstalk cancellation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional crosstalk cancellation techniques are used to handle six-degrees of freedom head movements, then crosstalk cancellation coverage is improved, but computational resources required become exponentially higher

Engineering Contradiction:
Improvecrosstalk cancellation coverageVSAvoidcomputational resources
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the continuous six-degree-of-freedom space into a discrete grid of measurement points. Instead of computing crosstalk cancellation for all possible continuous head positions and orientations, the system pre-measures transfer functions at discrete grid points and uses interpolation to handle intermediate positions. This segmentation reduces the computational burden from infinite continuous calculations to a manageable discrete set of pre-computed values.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary measurements of transfer functions at discrete grid points covering the six-degree-of-freedom space before actual audio playback. These pre-computed transfer functions are stored in a lookup table, allowing the system to quickly retrieve and interpolate appropriate values during real-time operation without performing complex calculations on the fly.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If conventional crosstalk cancellation techniques are focused on a specific point in three-dimensional space, then measurement precision is improved, but adaptability to user movement deteriorates

Engineering Contradiction:
Improvecrosstalk cancellation accuracyVSAvoidhandling of head movement
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent extends the traditional three-dimensional spatial mapping to a six-dimensional space by incorporating three rotational degrees of freedom (pitch, yaw, roll) in addition to the three translational degrees of freedom (x, y, z position). This dimensional expansion creates a comprehensive grid that accounts for both position and orientation of the user's head, allowing accurate crosstalk cancellation regardless of head movement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a dynamic interpolation system that adapts to real-time head movements. Instead of using fixed transfer functions for specific positions, the system continuously interpolates between pre-measured grid points based on the user's current head position and orientation, providing dynamically updated crosstalk cancellation that follows the user's movements.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4583540A1Multidimensional acoustic crosstalk cancellation filter interpolation
Publication Date: 2025.07.09 HARMAN INT IND INC
  • EP4583540A1 patent drawingFigure 1
  • EP4583540A1 patent drawingFigure 2
  • EP4583540A1 patent drawingFigure 3

AI summary

Various embodiments disclose a computer-implemented method comprising determining a position and an orientation of a user in an environment, determining, based on the position and the orientation of the user, a subset of nearest points in a dimensional map, each point is associated with a corresponding transfer function, determining, based on the distance between each point in the subset of nearest points to the position and the orientation of the user in the dimensional map, a respective weight for each transfer function associated with the subset of nearest points, determining at least one crosstalk cancellation filter by combining each of the transfer functions associated with the subset of nearest points based on the respective weights, generating a plurality of audio signals for a plurality of loudspeakers based on the at least one crosstalk cancelation filter, and transmitting the plurality of audio signals to the plurality of loudspeakers for output.