Interaural Time Delay Crossfading for Click-Free Binaural Rendering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In virtual reality, augmented reality, and mixed-reality environments, accurately presenting interaural time differences (ITDs) to simulate the spatial origin of audio sources is crucial for immersion, but rapid changes can introduce sonic artifacts like 'clicking' sounds, compromising the believability of the soundscape.
Innovation Solution
A wearable head device processes audio signals by applying interaural time delays and head-related transfer functions (HRTFs) to generate left and right output audio signals, minimizing sonic artifacts through delay processing and gain adjustments, and using cross-fading techniques to smoothly transition between delay values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If rapid changes to audio signals are applied to adjust the soundscape to reflect positions and orientations, then the spatial accuracy of audio sources is improved, but sonic artifacts such as clicking sounds are introduced
Solution Approach 1:
The system pre-calculates and stores multiple delay values corresponding to different possible source positions and orientations. When the user or object moves, the system prepares the next delay value in advance and transitions smoothly between pre-computed values, avoiding real-time calculation artifacts and enabling rapid spatial adjustments without clicking sounds.
Solution Approach 2:
The system dynamically adjusts the interaural time delay based on the current source position and orientation, using cross-fading techniques to smoothly transition between delay values. This dynamic approach maintains spatial accuracy while eliminating abrupt changes that cause sonic artifacts.
2Reliability
If complex processing is applied to accurately present interaural time differences, then the spatial realism is improved, but the computational efficiency deteriorates
Solution Approach 1:
The system pre-calculates delay values for all possible source positions and orientations before runtime, storing them in a lookup table. During actual operation, the system only needs to retrieve and apply the appropriate pre-computed delay value based on current position and orientation data, maintaining spatial realism while dramatically reducing computational overhead.
Solution Approach 2:
The system changes the approach from real-time complex calculation to parameter-based lookup, where the interaural time delay is determined by selecting from pre-computed parameters based on source position and orientation. This parameter change maintains accuracy while improving computational efficiency.
Data Source
AI summary
Examples of the disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. According to an example method, a first input audio signal is received, the first input audio signal corresponding to a source location in a virtual environment presented to the user via the wearable head device. The first input audio signal is processed to generate a left output audio signal and a right output audio signal. The left output audio signal is presented to the left ear of the user via a left speaker associated with the wearable head device. The right output audio signal is presented to the right ear of the user via a right speaker associated with the wearable head device. Processing the first input audio signal comprises applying a delay process to the first input audio signal to generate a left audio signal and a right audio signal; adjusting a gain of the left audio signal; adjusting a gain of the right audio signal; applying a first head-related transfer function (HRTF) to the left audio signal to generate the left output audio signal; and applying a second HRTF to the right audio signal to generate the right output audio signal. Applying the delay process to the first input audio signal comprises applying an interaural time delay (ITD) to the first input audio signal, the ITD determined based on the source location.