Ear Shape Analysis Device for Head-Related Transfer Function Accuracy
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Solution Overview
Problem
Existing methods for calculating head-related transfer functions often fail to accurately represent individual ear shapes, leading to poor sound image localization for listeners, especially when using dummy heads or insufficient measurement accuracy.
Innovation Solution
An ear shape analysis device generates an average ear shape by comparing multiple sample ears to a reference ear, creating a head-related transfer function that comprehensively reflects shape tendencies, allowing a large number of listeners to properly perceive sound image locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If head-related transfer functions are calculated using dummy head measurements, then measurement burden on listeners is reduced, but sound image localization accuracy deteriorates
Solution Approach 1:
The patent creates a virtual copy of the listener's actual ear shape by capturing photographs from multiple directions and generating a three-dimensional ear shape model. This virtual model is then used to calculate personalized head-related transfer functions, achieving both ease of measurement (no physical burden) and high accuracy (matches individual ear geometry).
Solution Approach 2:
The patent replaces the mechanical measurement system (physical dummy head or direct ear measurement) with a photogrammetry-based optical system. By using multiple photographs and image processing algorithms, the system reconstructs ear geometry without physical contact or burden on the listener, thereby reducing measurement burden while maintaining accuracy.
2Measurement precision
If head-related transfer functions are calculated using individual ear shape measurements, then sound image localization accuracy is improved, but measurement burden on listeners increases
Solution Approach 1:
The patent creates a virtual copy of the listener's actual ear shape by capturing photographs from multiple directions and generating a three-dimensional ear shape model. This virtual model is then used to calculate personalized head-related transfer functions, achieving both ease of measurement (no physical burden) and high accuracy (matches individual ear geometry).
Solution Approach 2:
The patent introduces photographs as an intermediary medium between the listener and the measurement system. Instead of directly measuring the ear (which causes burden), the system captures images and processes them to extract ear geometry, thereby eliminating direct physical measurement while preserving accuracy.
3Adaptability or versatility
If multiple sample ears are analyzed to generate average ear shape, then applicability to large number of listeners is improved, but processing complexity increases
Solution Approach 1:
The patent segments the ear shape analysis into distinct processing stages: photograph acquisition from multiple directions, three-dimensional model generation for each sample ear, ear shape data extraction, and averaging computation. This segmentation allows complex processing to be organized systematically, managing complexity while enabling batch processing of multiple sample ears.
Solution Approach 2:
The patent performs preliminary processing by generating three-dimensional ear shape models and extracting ear shape data from multiple sample ears before computing the average. This preliminary action organizes the data in a standardized format, making the subsequent averaging process more efficient and manageable, thereby handling multiple listeners' data systematically.
Data Source
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AI summary
An ear shape analyzer includes: a sample ear analyzer configured to generate, for each of N sample ears, an ear shape data set that represents a difference between a point group representative of a three-dimensional shape of a reference ear and a point group representative of a three-dimensional shape of one of the N sample ears; an averaging calculator configured to generate averaged shape data by averaging N ear shape data sets generated by the sample ear analyzer; an ear shape identifier configured to identify an average ear shape of the N sample ears by translating coordinates of respective points of the point group representing the three-dimensional shape of the reference ear, by using the averaged shape data.