Virtual Microphone Bubbles for 3D Sound Source Localization
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Solution Overview
Problem
Existing microphone array technologies struggle to provide even sound coverage and precise sound source location in multi-user conference settings, especially with dynamic participant positions and varying noise sources, leading to suboptimal audio quality and increased complexity.
Innovation Solution
The system employs a dynamic microphone array that forms thousands of virtual microphone bubbles across a room, allowing for even sound coverage and precise 3D location determination of sound sources. This is achieved through the use of a bubble processor that calculates processing gains at each virtual microphone location, focusing the array on specific sound sources while minimizing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional distributed microphones are used close to participants, then sound pick up quality is improved, but hardware complexity and installation complexity increase
Solution Approach 1:
The patent creates virtual microphone copies at multiple 3D positions in space through signal processing. Instead of physically placing microphones at every participant location, the system processes signals from a limited number of physical microphones to generate virtual microphone signals that appear to come from any position in the room, thereby achieving high-quality sound pickup without increasing hardware complexity
2Measurement precision
If microphone beam arrays are used to steer towards desired sounds, then sound quality gain is achieved, but the array cannot locate sound precisely in 3D space and coverage is uneven
Solution Approach 1:
The patent extends traditional 2D beamforming to 3D spatial audio processing. By introducing the vertical dimension and creating virtual microphones throughout the 3D space rather than just in a plane, the system achieves precise 3D sound source localization and even coverage throughout the entire room volume, overcoming the limitations of conventional 2D beam arrays
3Measurement precision
If beam forming arrays are used, then sound quality is improved, but post-processing is required which adds artifacts and processing distortion
Solution Approach 1:
The patent performs focus determination and virtual microphone selection in advance before final audio processing. By pre-calculating which virtual microphones provide the best signal quality and focusing on those sources, the system avoids the need for aggressive post-processing normalization and artifact reduction, thereby maintaining higher audio quality with minimal distortion
4Device complexity
If a limited number of physical microphones are used, then cost and installation complexity are reduced, but even coverage of the room and precise sound source location determination become difficult
Solution Approach 1:
The patent generates multiple virtual microphone copies from a limited set of physical microphones through sophisticated signal processing. Each virtual microphone represents a different 3D position in the room, allowing the system to achieve precise sound source localization and even coverage as if hundreds of physical microphones were present, while using only a small number of actual hardware devices
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
This approach provides natural and consistent audio experiences by maintaining a consistent noise floor, allowing for effective sound source focusing and optimization, and reducing artifacts and distortion associated with traditional beam-forming arrays.
Implementation Method 1
determining a set of time delays for the plurality of microphones based on a presumed location of the sound source in the shared space
Implementation Method 2
focusing the array on specific sound sources while minimizing noise
Data Source
Figure 1a~1b
Figure 2
Figure 3a~3b
AI summary
Focusing sound signals in a shared 3D space uses an array of physical microphones, preferably disposed evenly across a room to provide even sound coverage throughout the room. At least one processor coupled to the physical microphones does not form beams, but instead preferably forms 1000's of virtual microphone bubbles within the room. By determining the processing gains of the sound signals sourced at each of the bubbles, the location(s) of the sound source(s) in the room can be determined. This system provides not only sound improvement by focusing on the sound source(s), but with the advantage that a desired sound source can be focused on more effectively (rather than steered to) while un-focusing undesired sound sources (like reverb and noise) instead of rejecting out of beam signals. This provides a full three dimensional location and a more natural presentation of each sound within the room.