Head-Mounted HRTF Measurement for Personalized Spatial Audio
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Solution Overview
Problem
Existing methods for measuring head-related transfer functions (HRTFs) are cumbersome, requiring large equipment and imposing a significant measurement burden on users, while using average characteristics reduces the realism of stereophonic sound reproduction.
Innovation Solution
An information processing apparatus and method that uses a portable system with a terminal apparatus mounted on the user's head, combined with a control box and acoustic signal generation units, to measure HRTFs efficiently by interpolating data from multiple positions using spherical coordinates, allowing accurate HRTF derivation without large-scale equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large speaker traverse is used to measure HRTFs at equal intervals, then measurement accuracy is improved, but measurement burden on the user increases and device complexity increases
Solution Approach 1:
Instead of moving the sound source around the user's head (conventional approach), the patent inverts the approach by moving the user's head to different positions relative to a fixed sound source. This is achieved by having the user wear a terminal apparatus with microphone and move their head to predetermined positions, while the sound source remains stationary. This inversion significantly reduces the complexity of the measurement system while maintaining measurement accuracy.
Solution Approach 2:
The patent uses a dummy head microphone that simulates the user's head and ears to capture sound. This dummy head serves as a simplified copy of the actual human head, allowing for easier measurement while still obtaining accurate HRTF data. The dummy head microphone is positioned at the center of a sphere, and the user's head movements are used to create the necessary spatial variations in sound capture.
2Measurement precision
If a large speaker traverse is used to measure HRTFs at equal intervals, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
Instead of moving the sound source around the user's head (conventional approach), the patent inverts the approach by moving the user's head to different positions relative to a fixed sound source. This is achieved by having the user wear a terminal apparatus with microphone and move their head to predetermined positions, while the sound source remains stationary. This inversion significantly reduces the complexity of the measurement system while maintaining measurement accuracy.
Solution Approach 2:
The patent uses a dummy head microphone that simulates the user's head and ears to capture sound. This dummy head serves as a simplified copy of the actual human head, allowing for easier measurement while still obtaining accurate HRTF data. The dummy head microphone is positioned at the center of a sphere, and the user's head movements are used to create the necessary spatial variations in sound capture.
3Ease of operation
If a dummy head microphone simulating average user characteristics is used, then measurement burden is reduced, but realism of stereophonic sound reproduction decreases
Solution Approach 1:
Instead of using a stationary dummy head with average characteristics, the patent inverts the approach by having the user actively move their own head to different positions. This allows the measurement to capture the user's actual head and ear characteristics rather than average characteristics, improving the realism of sound reproduction while keeping the measurement process relatively simple.
Solution Approach 2:
The patent pre-determines a set of head positions and orientations that the user should assume during measurement. These predetermined positions are calculated based on spherical coordinates and correspond to specific measurement points. By providing these instructions in advance, the user knows exactly what movements to make, reducing the complexity of the measurement process while still obtaining personalized HRTF data.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate and efficient measurement of HRTFs with minimal user burden, allowing for personalized and realistic stereophonic sound reproduction without the need for extensive setup or specialized environments.
Implementation Method 1
a sound source 106 to output an acoustic signal
Data Source
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AI summary
Provided is an information processing apparatus that carries out a process of deriving a head related transfer function. The information processing apparatus includes a detection unit that detects a position of a head of a user, a storage unit that stores a head related transfer function of the user, a determination unit that determines a position of a sound source for measuring the head related transfer function of the user based on the position of the head detected by the detection unit and information stored in the storage unit, a control unit that controls the sound source to output measurement signal sound from the position determined by the determination unit, and a calculation unit that calculates the head related transfer function of the user based on collected sound data obtained by collecting, at the position of the head, the measurement signal sound output from the sound source.