HRTF Selection Using Morphological Parameters and Perceptual Databases

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Solution Overview

Problem

Current methods for selecting Head-Related Transfer Function (HRTF) filters in databases lack reliability and do not prioritize perceptual quality, making them unsuitable for general public applications, especially in binaural synthesis where individualized HRTFs are crucial for precise spatial sound localization.

Innovation Solution

A method that uses perceptual listening tests to create an optimized multidimensional HRTF space by correlating morphological parameters with HRTF classifications, allowing for the selection of the most relevant HRTFs based on user-specific measurements, optimizing spatial perception and listening quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HRTF filters are selected using traditional statistical methods without perceptual validation, then the selection process is simpler and faster, but the reliability and perceptual quality of the selected HRTFs deteriorate

Engineering Contradiction:
Improvereliability in HRTF selectionVSAvoidcomplexity of selection method
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-collecting and organizing HRTF measurements from multiple subjects along with their morphological parameters in databases before actual selection occurs. Listening tests are conducted in advance to establish perceptual quality criteria, and multidimensional spaces are pre-computed based on morphological parameters. This preparation work enables fast, reliable selection during actual use without performing complex measurements and analyses in real-time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces multidimensional spaces as intermediaries between morphological parameters and HRTF selection. These spaces are constructed using principal component analysis on morphological data and serve as a bridge that maps user morphology to appropriate HRTFs. The intermediary space incorporates perceptual quality information from listening tests, enabling reliable selection without directly comparing all HRTF pairs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If individualized HRTF measurements are performed for each user, then the spatial localization precision is improved, but the time and cost required increases significantly

Engineering Contradiction:
Improveprecision in spatial localizationVSAvoidtime for HRTF measurement
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses copying by measuring morphological parameters (which are easy and fast to obtain) and using these measurements to select from pre-recorded HRTF databases. Instead of performing time-consuming individualized HRTF measurements for each user, the system copies the approach of measuring simple morphological features and matching them to stored HRTF data that was collected from multiple subjects during database construction.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent applies preliminary action by pre-collecting HRTF measurements from multiple subjects and organizing them in databases with associated morphological parameters before actual user selection occurs. This preparation work enables fast, reliable selection during actual use without performing complex measurements in real-time.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If the database contains HRTFs from many subjects, then the probability of finding a matching HRTF increases, but the complexity of managing and searching the database increases

Engineering Contradiction:
Improveapplicability to different usersVSAvoidcomplexity of database management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by organizing the database along multiple dimensions: morphological parameters (head size, ear shape, etc.), spatial positions, and perceptual quality ratings from listening tests. This multidimensional organization allows efficient searching and matching by projecting user morphology into the same parameter space, enabling the system to handle large databases with many subjects without excessive complexity.

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

Data Source

PatentEP2559265B1Method for selecting perceptually optimal HRTF filters in a database according to morphological parameters
Publication Date: 2014.09.17 ARKAMYS
  • EP2559265B1 patent drawingFigure 1~2
  • EP2559265B1 patent drawingFigure 3
  • EP2559265B1 patent drawingFigure 4

AI summary

The invention relates to a method for selecting a perceptually optimal HRTF in a database according to morphological parameters. Said method uses a first database which includes the HRTFs of a plurality of subjects M, a second database which includes the morphological parameters of the subjects, and a third database which corresponds to a perceptual classification of the HRTFs. According to the invention, the N most relevant morphological parameters are sorted by correlating the second and third databases. A multidimensional space is created, which optimises the spatial separation between the HRTFs according to the classification thereof in the third database such as to obtain an optimised space. An optimised projection model MPO is calculated, which is suitable for correlating K optimal morphological parameters with the corresponding position of the HRTF filters in the optimised space. The invention thus enables the selection, for any user whose HRTF is not included in the database, of at least one HRTF from the database BD1 according to the parameters K of said user and the optimised projection model MPO.