Spatial Audio Encoding for Flexible Microphone Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for a practical approach to facilitate ambisonic capture of live audio scenes using consumer devices, which must support a flexible number and arrangement of microphones, as existing methods are not well-suited for consumer devices.
Innovation Solution
An audio signal encoder is provided for consumer devices with multiple microphones, which includes a processor and a non-transitory computer-readable medium containing instructions to determine the number and directions of arrival of directional audio sources, and to encode active and passive microphone signal components into specific spatial output formats, enabling ambisonic capture and encoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If compact microphone arrays are used for spatial capture on consumer devices, then the device portability and consumer accessibility are improved, but the flexibility in supporting various numbers and arrangements of microphones is reduced
Solution Approach 1:
The encoding system is designed to universally handle different microphone configurations by determining directions of arrival and decomposing signals based on actual microphone arrangements rather than requiring fixed compact array geometries. The system adapts to various numbers and positions of microphones while maintaining ambisonic encoding capability.
Solution Approach 2:
The system dynamically determines the number and directions of arrival of audio sources based on the actual microphone signals received, rather than relying on predetermined static array configurations. This allows the encoding process to adapt in real-time to different microphone arrangements on consumer devices.
2Measurement precision
If active and passive signal decomposition is performed, then the encoding accuracy for directional audio sources is improved, but the computational complexity increases
Solution Approach 1:
The audio signal is segmented into active components (from identified directional sources) and passive components (remaining ambient sound). This segmentation allows targeted processing of directional sources while simplifying handling of the residual field, improving encoding accuracy without requiring full complex processing of the entire signal.
Solution Approach 2:
The system uses the microphone array's own spatial information and direction of arrival estimates to automatically decompose the signal into active and passive components, eliminating the need for external calibration or manual configuration. The encoding process self-adapts to the actual acoustic environment and microphone setup.
Data Source
AI summary
A method to encode audio signals is provided for use with an audio capture device that includes multiple microphones having a spatial arrangement on the device, a method to encode audio signals comprising: receiving multiple microphone signals corresponding to the multiple microphones; determining a number and directions of arrival of directional audio sources represented in the one or more microphone signals; determining one of an active microphone signal component and a passive microphone signal component, based upon the determined number and directions of arrival; determining the other of the active microphone signal component and the passive microphone signal component, based upon the determined one of the active input spatial audio signal component and the passive input spatial audio signal component; encoding the active microphone signal component; encoding the passive microphone signal component.