Ear Image Matching for HRTF Personalization

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Solution Overview

Problem

Current methods for determining head-related transfer functions (HRTFs) are time-consuming, expensive, and cumbersome, requiring numerous measurements in an anechoic chamber.

Innovation Solution

A method and system that use reference images of ears associated with pre-determined HRTF information to select the appropriate HRTF by comparing an input image of a subject's ear with stored reference images, using a processor to determine the best match and transmit the corresponding HRTF information for configuring hearing aids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional anechoic chamber measurement methods are used to determine HRTF, then measurement precision is improved, but loss of time and device complexity increase significantly

Engineering Contradiction:
ImproveHRTF measurement accuracyVSAvoidTime required for HRTF determination
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent creates a database of reference images of ears with associated HRTF information. Instead of performing time-consuming physical measurements on each subject, the system captures an image of the subject's ear, compares it against the reference database, and selects the matching HRTF. This copying approach replaces actual measurement with image matching, dramatically reducing time while maintaining accuracy through the reference database.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent performs preliminary work by creating a comprehensive database of reference ear images with pre-measured HRTF information before actual use. This preliminary action allows the system to quickly match new subjects against pre-prepared references, avoiding the need to perform full measurements during the fitting process itself.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If traditional anechoic chamber measurement methods are used to determine HRTF, then measurement precision is improved, but cost and device complexity increase

Engineering Contradiction:
ImproveHRTF measurement accuracyVSAvoidComplexity of HRTF determination system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical measurement system (anechoic chamber, precision positioning equipment, physical microphones) with an optical/image-based system. A camera captures ear images, and software algorithms perform pattern matching against the reference database. This substitution eliminates the need for expensive, complex physical measurement infrastructure while maintaining measurement capability through digital image processing.

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

3Productivity

If image-based reference matching is used to determine HRTF, then productivity and ease of operation are improved, but measurement precision may be compromised

Engineering Contradiction:
ImproveSpeed of HRTF determinationVSAvoidHRTF measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The reference database contains HRTF information that has been pre-measured with high precision using traditional methods. By performing the accurate measurement in advance and storing it with corresponding ear images, the system can quickly retrieve and apply pre-verified accurate HRTF data without repeating the measurement process, thus maintaining precision while achieving high speed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates accurate copies of ear geometry and acoustic properties from the reference database. By matching the subject's ear image to the most similar reference image, the system copies the associated HRTF characteristics, transferring pre-measured accuracy to the new subject through digital pattern recognition rather than physical measurement.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP2611216B1Systems and methods for determining head related transfer functions
Publication Date: 2015.12.16 GN HEARING AS
  • EP2611216B1 patent drawingFigure 1
  • EP2611216B1 patent drawingFigure 2
  • EP2611216B1 patent drawingFigure 3

AI summary

A method for determining HRTF includes obtaining a plurality of reference images of different respective ears, one or more of the reference images associated with a corresponding pre-determined HRTF information, obtaining information regarding an input image that includes an image of an ear of a subject, comparing the information regarding the input image with information regarding the reference images using a processor, and selecting one of the pre-determined HRTF information based at least in part on a result of the act of comparing.