Position-Aware Audio Filtering for Extra-Aural Spatial Sound
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods of generating and applying head-related transfer functions (HRTFs) assume that headphones emit spatialized sound directly into the ear canal entrance, which is erroneous for extra-aural devices, leading to imperfect sound representation due to additional artifacts.
Innovation Solution
An audio system and method to determine an audio filter that compensates for the relative positioning between an electroacoustic transducer and anatomical features by using a remote device to capture images of the audio device worn on the user's head, determining the relative position, and applying an audio filter to compensate for these artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If HRTFs are applied assuming direct emission into ear canal, then spatial audio rendering is simplified, but sound representation becomes inaccurate for extra-aural devices
Solution Approach 1:
The system performs preliminary image capture of the audio device worn on the user's head before audio rendering. This preliminary action allows the system to determine the actual relative position between the electroacoustic transducer and anatomical features, enabling accurate spatial audio rendering that accounts for the specific device anatomy and user fit.
Solution Approach 2:
The system uses feedback from captured images to determine the actual device-to-anatomical-position relationship. By continuously or periodically capturing images and processing them to find relative positions, the system adjusts the spatial audio rendering to compensate for deviations from ideal direct-emission geometry, thereby maintaining accuracy.
2Ease of operation
If extra-aural headphones are used with standard HRTFs, then device comfort and wearability improve, but additional artifacts are introduced in sound transmission
Solution Approach 1:
The system changes the parameter of spatial audio rendering by adjusting HRTF application based on captured images showing the actual device position and orientation on the user's head. This allows the system to compensate for acoustic artifacts introduced by the extra-aural configuration and user-specific fit, maintaining sound accuracy while preserving wearability.
3Measurement precision
If user-specific HRTFs are measured in laboratory, then spatial audio accuracy improves, but measurement time and complexity increase
Solution Approach 1:
Instead of performing complex laboratory measurements, the system uses a camera to capture an image copy of the audio device worn on the user's head. From this visual copy, the system extracts geometric information about device positioning and orientation, which is then used to determine appropriate spatial audio parameters. This copying approach provides user-specific accuracy without requiring time-consuming laboratory procedures.
4Measurement precision
If image capture is performed to determine device position, then spatial audio accuracy improves, but system complexity increases
Solution Approach 1:
The system replaces complex mechanical or sensor-based positioning systems with a simpler optical imaging approach. By using a camera to capture images of the device on the user's head and processing these images to determine relative positions, the system achieves accurate device positioning with reduced hardware complexity compared to traditional mechanical or radar-based positioning systems.
Data Source
AI summary
An audio system and a method of determining an audio filter based on a position of an audio device of the audio system, are described. The audio system receives an image of the audio device being worn by a user and determines, based on the image and a known geometric relationship between a datum on the audio device and an electroacoustic transducer of the audio device, a relative position between the electroacoustic transducer and an anatomical feature of the user. The audio filter is determined based on the relative position. The audio filter can be applied to an audio input signal to render spatialized sound to the user through the electroacoustic transducer, or the audio filter can be applied to a microphone input signal to capture speech of the user by the electroacoustic transducer. Other aspects are also described and claimed.