Iterative HRTF Refinement via User Feedback

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Solution Overview

Problem

Existing audio systems in artificial reality struggle to accurately calculate head-related transfer functions (HRTFs) for users, leading to inconsistencies in sound presentation, as they rely on static estimates without active or passive user feedback, which can result in inaccurate sound localization.

Innovation Solution

An iterative process is employed where an audio system generates an initial set of HRTFs using machine learning and computer vision, and then refines them through user feedback by presenting test sounds at specific locations, adjusting test locations based on user responses, until a threshold accuracy is achieved or a set period expires.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If static estimated HRTFs are used without user feedback, then computational demands and time are reduced, but sound localization accuracy deteriorates

Engineering Contradiction:
Improvesound localization accuracyVSAvoidtime for HRTF estimation
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system implements an iterative feedback mechanism where user responses to test sounds are collected and used to refine HRTF estimates. The process presents test sounds at specific locations, monitors user responses (such as gaze direction or head movement), and uses this feedback to update the HRTF model, progressively improving sound localization accuracy

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The HRTF estimation process transitions from a static approach to a dynamic iterative process. The system adapts the HRTF model in real-time based on user feedback, adjusting test locations and sound parameters across multiple iterations to optimize accuracy while managing computational resources

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If iterative refinement with user feedback is implemented, then HRTF accuracy is improved, but computational demands and time increase

Engineering Contradiction:
ImproveHRTF calculation accuracyVSAvoidcomputational demands
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The HRTF estimation process is divided into discrete iterations, each focusing on specific aspects of the transfer function. Test locations are selected and processed in sequential batches, allowing the system to manage computational complexity by breaking down the overall task into smaller, manageable segments

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts parameters such as test location selection, sound frequency content, and presentation intensity across iterations. By changing these parameters based on previous iteration results, the system optimizes the balance between accuracy improvement and computational efficiency

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11523240B2Selecting spatial locations for audio personalization
Publication Date: 2022.12.06 META PLATFORMS TECHNOLOGIES LLC
  • US11523240B2 patent drawing
  • US11523240B2 patent drawing
  • US11523240B2 patent drawing

AI summary

An audio system generates customized head-related transfer functions (HRTFs) for a user. The audio system receives an initial set of estimated HRTFs. The initial set of HRTFs may have been estimated using a trained machine learning and computer vision system and pictures of the user's ears. The audio system generates a set of test locations using the initial set of HRTFs. The audio system presents test sounds at each of the initial set of test locations using the initial set of HRTFs. The audio system monitors user responses to the test sounds. The audio system uses the monitored responses to generate a new set of estimated HRTFs and a new set of test locations. The process repeats until a threshold accuracy is achieved or until a set period of time expires. The audio system presents audio content to the user using the customized HRTFs.