Headset HRTF Compensation Using Distortion Mapping And Interpolation

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Solution Overview

Problem

Conventional methods for determining head-related transfer functions (HRTFs) are inefficient in terms of hardware resources and time, requiring complex infrastructure and taking a long time to achieve high-quality spatialization of audio content.

Innovation Solution

A method that captures audio data through a headset microphone, calculates individualized HRTFs by discarding distorted portions using a distortion mapping, and generates compensating HRTFs via interpolation, reducing the need for a sound dampening chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional HRTF measurement methods are used in sound dampening chambers with speaker arrays, then measurement precision is improved, but device complexity and time consumption increase significantly

Engineering Contradiction:
ImproveHRTF measurement precisionVSAvoidmeasurement infrastructure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses pre-measured HRTF data from test users as a reference model (copy) to estimate individual user HRTFs. Instead of performing complex physical measurements for each user, the system captures audio data from the user wearing the headset and compares it against the pre-existing distortion mapping created from test measurements, thereby obtaining individualized HRTFs without requiring complex measurement infrastructure.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical measurement system (sound dampening chamber, speaker arrays, microphones) with a computational approach. The system uses audio processing and mathematical modeling to estimate HRTFs by comparing captured audio data against pre-measured reference data, substituting physical measurement infrastructure with signal processing algorithms.

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

2Measurement precision

If conventional HRTF measurement methods are used with multiple speaker locations and repetitions, then measurement precision is improved, but time consumption increases to over an hour

Engineering Contradiction:
ImproveHRTF measurement precisionVSAvoidHRTF measurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs HRTF measurements for multiple test users in advance to create a pre-computed distortion mapping. This preliminary action stores the characteristic distortion patterns of the headset in a reference database, so that when an individual user needs HRTFs, the system only needs to capture audio data and compare it against the pre-existing mapping, dramatically reducing the time required for individual measurements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses pre-measured HRTF data from test users as reference models to estimate individual user HRTFs through comparison and interpolation, avoiding the need to perform time-consuming measurements for each individual user while maintaining measurement precision.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If HRTFs are measured with headset worn to ensure accuracy for headset users, then adaptability is improved, but measurement accuracy deteriorates due to sound distortion by headset

Engineering Contradiction:
Improveheadset-specific HRTF accuracyVSAvoidHRTF measurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent converts the harmful effect of headset-induced sound distortion into a beneficial feature. By measuring HRTFs with the headset worn for multiple test users and storing these distorted patterns as a reference distortion mapping, the system learns the characteristic distortion signature of the headset. This reference mapping is then used to compensate for and remove the distortion effects when measuring individual user HRTFs, thereby improving both adaptability to headset users and measurement accuracy.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system uses the pre-measured distortion mapping as feedback to correct individual user measurements. By comparing captured audio data against the reference distortion patterns and applying compensatory transformations, the system iteratively refines the HRTF estimates to account for headset effects, improving measurement accuracy while maintaining headset-specific adaptability.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3918817B1Compensating for effects of headset on head related transfer functions
Publication Date: 2025.08.13 META PLATFORMS TECHNOLOGIES LLC
  • EP3918817B1 patent drawingFigure 1A
  • EP3918817B1 patent drawingFigure 1B
  • EP3918817B1 patent drawingFigure 2

AI summary

An audio system captures audio data of test sounds through a microphone of a headset worn by a user. The test sounds are played by an external speaker, and the audio data includes audio data captured for different orientations of the headset with respect to the external speaker. A set of head-related transfer function (HRTFs) is calculated based at least in part on the audio data of the test sounds at the different orientations of the headset. A portion of the set of HRTFs is discarded to create an intermediate set of HRTFs. The discarded portion corresponding to one or more distortion regions that are based in part on wearing the headset. One or more HRTFs are generated that correspond to the discarded portion using at least some of the intermediate set of HRTFs to create an individualized set of HRTFs for the user.