Audio Signal Propagation Simulation Reducing Phase Artifacts
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Solution Overview
Problem
Existing methods for simulating early reflections in virtual environments often result in undesired phase artifacts due to constructive and destructive interference from multiple reflections with slightly differing delays, which can lead to a distracting "whooshing" sound and detract from the immersive experience.
Innovation Solution
A computer-implemented method that simulates the propagation of an audio signal in a virtual environment by determining a plurality of audio paths between a source and receiver, identifying paths with delays causing interference, and applying adjustments such as culling, intensity reduction, or delay shifting to minimize phase artifacts while maintaining spatial information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple reflections of the same signal are simulated with slightly differing delays, then the spatial information and realism of the virtual environment is improved, but phase artifacts and interference patterns are generated that detract from the immersive experience
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the delay values of reflected audio paths based on the detected prominent frequencies of the audio signal. When a reflection path's delay is close to a half-integer multiple of the wavelength of a prominent frequency, the system modifies the delay parameter to avoid constructive and destructive interference that causes phase artifacts. This resolves the contradiction by changing the delay parameter to eliminate harmful phase artifacts while preserving the spatial information provided by the reflection paths.
2Manufacturing precision
If audio paths are adjusted to reduce phase artifacts, then audio quality is improved, but the spatial information provided by early reflections may be compromised
Solution Approach 1:
The patent applies local quality by selectively adjusting only those specific audio paths that cause phase artifacts, rather than uniformly modifying all reflection paths. The system identifies paths with delays close to half-integer multiples of prominent wavelengths and applies adjustments only to those paths. This localized approach preserves the spatial information provided by other reflection paths while eliminating the harmful phase artifacts from problematic paths, thus resolving the contradiction between audio quality and spatial information preservation.
3Object-affected harmful factors
If the simulation is adapted to the specific audio signal to reduce phase artifacts, then the harmful interference is reduced, but the computational complexity increases
Solution Approach 1:
The patent applies partial action by focusing computational resources on identifying and adjusting only the most problematic audio paths - those with delays close to half-integer multiples of prominent wavelengths. Rather than analyzing and adjusting all reflection paths equally, the system selectively processes paths that are most likely to cause phase artifacts. This partial approach reduces computational complexity while still achieving significant interference reduction, resolving the contradiction between harmful factor reduction and computational complexity.
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 method effectively reduces phase artifacts by dynamically adjusting specific audio paths based on the audio content, thereby improving the overall audio quality and immersion in virtual environments without compromising the spatial information provided by early reflections.
Implementation Method 1
Simulation of sound propagation involves simulating reflections of an audio signal emitted from an audio source as it propagates along a multitude of propagation paths to a receiver and is reflected from surfaces within the virtual environment
Implementation Method 2
the playback of multiple copies of the same signal with slightly differing delays causes constructive and destructive interference, resulting in a 'whooshing' sound
Data Source
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AI summary
A computer-implemented method of simulating the propagation of an audio signal between a source and receiver in a virtual environment is disclosed. The method comprising: simulating reflections of an audio signal within the virtual environment to determine a plurality of audio paths between the source and receiver; determining an input audio signal to be propagated between the source and receiver by the plurality of audio paths; determining one or more audio paths having a delay that causes interference in the input audio signal; applying an adjustment to the determined audio paths to reduce the interference in the audio signal caused by the one or more audio paths. In this way, an audio simulation may be adapted according to the specific audio signal to reduce phase artefacts.