Ambisonic Audio Processing Using Omnidirectional Microphone Arrays
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Solution Overview
Problem
Current methods for broadcasting 360° video signals lack effective association with audio signals, limiting immersive experiences, as existing 3D audio technologies are expensive and reserved for professionals, while compact solutions like Eigenmike, Soundfield, and TetraMic are costly and limited to professional use.
Innovation Solution
A method for processing sound signals using a matrix calculation involving microphones arranged in a circle, with a bandpass filter and ambisonic format conversion, allowing for cost-effective 360° sound and image recording, enabling the use of existing devices like 360° cameras or mobile phones, and incorporating head orientation for personalized sound restitution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If professional 3D audio systems (Eigenmike, Soundfield, TetraMic) are used to achieve high spatial audio fidelity, then audio quality is improved, but device cost and complexity increase significantly
Solution Approach 1:
The patent replaces expensive professional microphone arrays with inexpensive omnidirectional microphones that can be integrated into common devices like smartphones and 360° cameras. This substitution maintains adequate spatial audio quality while dramatically reducing cost and complexity, making 360° audio accessible to consumer applications rather than just professional use.
Solution Approach 2:
The patent changes the operational parameters of the microphone system by using omnidirectional microphones with specific polar patterns and applying mathematical transformations (Ambisonics decoding) to reconstruct spatial audio information. This parameter change allows ordinary microphones to achieve spatial audio capabilities previously reserved for complex professional systems.
2Measurement precision
If professional 3D audio systems are used to capture spatial information, then audio quality is improved, but the systems become expensive and limited to professional use
Solution Approach 1:
The patent makes the 360° audio system universal by integrating omnidirectional microphones into multiple common devices including smartphones, 360° cameras, and virtual reality headsets. This multi-functionality approach allows the same audio capture technology to serve various consumer applications, dramatically improving accessibility while maintaining spatial audio quality.
Solution Approach 2:
By using inexpensive omnidirectional microphones instead of expensive professional microphones, the patent enables mass production and widespread adoption of 360° audio systems in consumer electronics, transitioning from professional-only accessibility to broad consumer availability.
3Device complexity
If standard geometric microphone arrays (dodecahedron, tetrahedron) are used, then conversion to ambisonic format is simplified, but adaptability to existing devices is limited
Solution Approach 1:
The patent breaks from traditional symmetric geometric arrays (dodecahedron, tetrahedron) by using omnidirectional microphones that can be arranged in asymmetric configurations suitable for existing devices like smartphones and 360° cameras. The mathematical transformation methods are adapted to handle these non-standard configurations, maintaining conversion simplicity while greatly improving device compatibility.
Solution Approach 2:
The patent makes the microphone array configuration dynamic and adaptable rather than fixed to specific geometric shapes. The system can accommodate various microphone placements and configurations found in different consumer devices, with the ambisonic decoding algorithms adjusting to the specific array geometry used.
4Loss of information
If 360° video broadcasting is implemented, then visual immersion is improved, but audio association remains inadequate
Solution Approach 1:
The patent merges 360° video and audio broadcasting into a unified spatially coherent system. By capturing both video and audio with synchronized omnidirectional sensors and processing them together through ambisonic decoding, the system maintains spatial coherence between visual and auditory information, creating a reliable immersive experience where audio and video are properly associated in the 360° space.
Data Source
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AI summary
This invention relates to a method of processing a sound signal that comprises the following steps: ·Synchronous reception of an input sound signal (Sinput) by means of N microphones, N being a natural number greater than or equal to three; ·Encoding of the said input sound signal (Sinput) in a data format (D) of sound, said encoding comprising a sub-step of transforming the input signal into an ambisonic format of order R, R being a natural number greater than or equal to one; the said sub-step of transformation into an ambisonic format is carried out by means of a Fast Fourier Transform, a matrix multiplication, an Inverse Fast Fourier Transform and by means of a band pass filter; and ·Return of an output sound signal (Soutput) by means of digital processing of the sound data (D). This invention also relates to a system of processing a sound signal.