Individualized HRTF Calculation via Ear Morphology Database

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Solution Overview

Problem

Current methods for personalizing head-related transfer functions (HRTFs) are inefficient and unreliable, particularly in terms of customization time and accuracy, as they often require extensive data and complex psycho-acoustic testing, and struggle to accurately determine the necessary morphological parameters for individualization.

Innovation Solution

A method and system that perform statistical analyses on 3D or 2D ear data and corresponding HRTFs to determine the links between ear morphology and HRTFs, allowing for the calculation of a transfer function tailored to an individual using a database of ear data and HRTFs, enabling real-time applications and overcoming physical modeling simplifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If finite element methods are used to calculate HRTFs at high frequencies with fine 3D meshes, then measurement precision is improved, but computation time becomes prohibitive

Engineering Contradiction:
ImproveHRTF calculation accuracyVSAvoidcomputation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores HRTF data in a database before actual use. During real-time applications, the pre-computed HRTF data is retrieved and applied directly, eliminating the need for expensive on-demand finite element calculations while maintaining high frequency accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of performing complex finite element calculations each time HRTFs are needed, the patent creates a database of pre-computed HRTF copies from finite element simulations. These copies are then used in place of real-time calculations, significantly reducing computation time while preserving measurement precision

Inventive Principle:
Principle #26Copying

2Reliability

If extensive psycho-acoustic testing is conducted to personalize HRTFs, then reliability of individualization is improved, but customization time increases significantly

Engineering Contradiction:
Improveindividualization accuracyVSAvoidcustomization time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts only the essential morphological parameters (ear shape, head size, torso dimensions) from the individual's physical characteristics. By focusing on these key parameters rather than conducting comprehensive psycho-acoustic testing, the system achieves reliable individualization with significantly reduced customization time

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/subjective psycho-acoustic testing process with an automated computational system that uses morphological measurements and statistical databases to determine personalized HRTFs, eliminating the need for time-consuming subjective testing while maintaining reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If physical modeling with detailed morphological parameters is used, then manufacturing precision of HRTF models is improved, but device complexity increases

Engineering Contradiction:
Improvemorphological model accuracyVSAvoidmodeling system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the complex physical modeling task into distinct components: a database of pre-computed HRTFs corresponding to specific morphological parameters, and a parameter matching system. This segmentation allows accurate modeling without requiring complex real-time simulations, as the heavy computational burden is separated into pre-processing

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3348079B1Method and system for developing a head-related transfer function adapted to an individual
Publication Date: 2020.05.13 MIMI HEARING TECHNOLOGIES GMBH
  • EP3348079B1 patent drawingFigure 1
  • EP3348079B1 patent drawingFigure 2
  • EP3348079B1 patent drawingFigure 3

AI summary

Method for developing a head-related transfer function (Sj) adapted to an individual, with the help of a database (OHi) comprising 3D or 2D ear data (0i) and corresponding head-related transfer functions (Hi), the method comprising the steps consisting in: - performing a statistical analysis (S2) of the 3D or 2D ear space of the database; - performing a statistical analysis (S3) of the head-related transfer space of the database; - performing an analysis of the links (S4) between parameters of the statistical analysis of the 3D or 2D ear space and parameters of the statistical analysis of the head-related transfer function space; and - determining (S5), with the help of said analysis of the links and of said statistical analysis of the 3D or 2D ear space, a function (OHi) for calculating a head-related transfer function (S j) with the help of data representative of at least one ear.