Co-located Acoustic Sensor Array for Sound Source Localization
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Solution Overview
Problem
Existing sound localization systems face limitations in accurately decomposing sound fields into direct and diffuse components across a wide range of frequencies due to spatial aliasing and attenuation issues, particularly with microphone arrays that rely on distance between microphones, leading to inadequate performance in noisy environments.
Innovation Solution
A system utilizing co-located acoustic sensor elements, including directional flow microphones oriented orthogonally to each other, processes signals to determine the direction and distance of sound sources by analyzing spatial coherence and energy ratios, enabling accurate direct/diffuse sound decomposition across the entire audible frequency range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If microphones are spaced apart by a long distance to measure larger time delays, then low frequency sound decomposition is improved, but spatial aliasing occurs for higher frequency components
Solution Approach 1:
The patent divides the acoustic measurement task into multiple segments by using multiple microphone pairs with different spacing distances. Each microphone pair is optimized for a specific frequency range: closer pairs for high frequencies and farther pairs for low frequencies. This segmentation allows the system to accurately decompose sound fields across the entire audible spectrum without suffering from spatial aliasing in any single frequency band.
Solution Approach 2:
The patent creates a multi-functional microphone array system where each microphone serves multiple purposes by participating in different spatial configurations. The same set of microphones can be paired differently to measure different frequency ranges, making the system universally applicable across all audible frequencies without requiring separate dedicated arrays for each frequency band.
2Reliability
If microphones are spaced apart by a short distance to avoid spatial aliasing, then high frequency measurement is improved, but time delay becomes too small for accurate low frequency decomposition
Solution Approach 1:
The patent segments the frequency spectrum into different bands and assigns different microphone spacing configurations to each band. Close-spaced microphone pairs handle high frequency measurements where small time delays are critical, while far-spaced pairs handle low frequency measurements where larger time delays are needed. This segmentation resolves the contradiction by ensuring each frequency range receives optimized measurement geometry.
Solution Approach 2:
The patent introduces a dimensional aspect by using multiple spatial configurations simultaneously. Instead of choosing a single fixed microphone spacing, the system creates multiple virtual measurement dimensions through different pairwise combinations, allowing independent optimization for different frequency ranges while maintaining coherence across the entire audio spectrum.
3Measurement precision
If directional acoustic sensor elements are used to improve sound localization accuracy, then direct sound isolation is enhanced, but device complexity increases
Solution Approach 1:
The patent merges multiple directional sensor elements into an integrated array where each element shares common preprocessing circuitry and computational resources. The directional characteristics of individual sensors are combined through coherent signal processing, achieving enhanced localization accuracy while minimizing the complexity increase that would result from completely independent sensor systems.
Solution Approach 2:
The patent utilizes parameter changes in the sensor elements themselves, specifically using flow-directional microphones with adjustable or fixed directional patterns. By modifying the directional response parameters of the sensors rather than relying solely on complex geometric arrangements, the system achieves improved localization accuracy with more manageable device 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
This approach provides more accurate sound localization and decomposition, overcoming the limitations of traditional systems by maintaining directivity and sensitivity across the entire audible range, enhancing the ability to isolate desired sound sources in noisy environments.
Implementation Method 1
The directional acoustic sensor element is responsive to flow associated with the incident sound
Data Source
AI summary
A system includes a plurality of acoustic sensor elements co-located with one another, each acoustic sensor element of the plurality of acoustic sensor elements being configured to generate a signal representative of sound incident upon the plurality of acoustic sensor elements, and a processor configured to determine data indicative of a location of a source of the sound based on the signals representative of the incident sound. The plurality of acoustic sensor elements include a directional acoustic sensor element configured to generate a signal representative of a directional component of the sound.