Peripheral-Anchored Spatial Audio Using HRTF and Motion Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Augmented reality audio systems struggle to effectively simulate sound sources at predetermined positions due to limitations in tracking and rendering audio signals, leading to a lack of realism and user dissatisfaction.
Innovation Solution
A wearable audio device and peripheral device system that tracks their respective positions and orientations, allowing for the generation of virtual sound sources anchored to the peripheral device, simulating direct and reflected audio paths using head-related transfer functions to enhance spatialization and realism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sound sources are simulated at predetermined positions using stereo headphones, then audio signals can be rendered to listeners, but the sound is perceived as coming from inside the listener's head rather than external locations
Solution Approach 1:
The patent replaces traditional stereo headphone rendering with a system that uses head-related transfer functions (HRTFs) to simulate acoustic propagation paths. This substitution transforms the mechanical/electrical signal delivery into a psychoacoustic model that replicates how sounds naturally reach the human ears from different spatial locations, enabling externalization of sound sources.
Solution Approach 2:
The system dynamically changes multiple audio parameters including time delays, attenuation levels, and spectral characteristics based on the relative positions and orientations of the wearable device and peripheral device. By adjusting these parameters in real-time according to spatial relationships, the system creates convincing externalized sound perceptions that move with the devices.
2Adaptability or versatility
If virtual sound sources are anchored to the peripheral device position, then spatialized audio can be produced, but the system complexity increases due to tracking and rendering requirements
Solution Approach 1:
The patent creates a universal spatial audio rendering system where the peripheral device serves multiple functions: it acts as both the audio source and the reference frame for spatial anchoring. The wearable device simultaneously performs head tracking and audio rendering while adapting to the peripheral device's position and orientation changes, reducing overall system complexity through functional integration.
Solution Approach 2:
The system introduces virtual sound sources as intermediary elements that mediate between the physical peripheral device and the listener's perception. These virtual sources are mathematically positioned based on device orientations and use HRTF filtering to create the final spatialized audio output, simplifying the rendering process by decoupling physical tracking from acoustic simulation.
3Reliability
If head-related transfer functions are used to simulate audio paths, then sound realism is enhanced, but computational processing requirements increase
Solution Approach 1:
The system applies HRTF filtering selectively rather than uniformly to all audio content. It focuses computational resources on simulating the most critical spatial characteristics needed for externalization while using simplified models for less important aspects, achieving acceptable realism with reduced processing demands compared to full-precision HRTF application.
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
The system provides spatialized and externalized audio that is 'pinned' to the peripheral device, enhancing the sense of realism by accurately simulating sound sources and their positions, orientations, and reflections, thereby improving the user experience.
Implementation Method 1
generate a first modified audio signal, wherein the first modified audio signal is modified using a first head-related transfer function (HRTF) based at least in part on the orientation of the wearable audio device relative to the peripheral device
Data Source
AI summary
Techniques and devices are described for generating modified audio signals. The techniques include receiving an audio signal at a device, tracking a movement of the device, generating a first modified audio signal to spatialize the audio signal, generating a second modified audio signal to spatialize the audio signal, causing the first modified audio signal to be rendered using a first speaker of the device, and causing the second modified audio signal to be rendered using a second speaker of the device. In some cases, the first modified audio signal is generated using a first head-related transfer function (HRTF) and the movement of the device, and the second modified audio signal is generated using a second HRTF and the movement of the device, where the second HRTF is different from the first HRTF. Numerous variations and configurations will be apparent in view of this disclosure.