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Design of robust concentric circular differential microphone arrays
Gongping Huang1, Jacob Benesty2, Jingdong Chen3
1Center of Intelligent Acoustics and Immersive Communications and School of Marine Science and Technology, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an 710072, China.
The Journal of the Acoustical Society of America
|June 11, 2017
Summary
This study introduces robust concentric circular differential microphone arrays (CCDMAs) to overcome limitations in traditional designs. CCDMAs effectively reduce white noise amplification and deep nulls, enhancing audio system performance.
Area of Science:
- Acoustics
- Signal Processing
- Array Signal Processing
Background:
- Circular differential microphone arrays (CDMAs) offer steering flexibility and high directivity but suffer from spatial aliasing, leading to white noise amplification and deep nulls.
- Existing solutions like minimum-norm filters improve white noise gain (WNG) but worsen array aperture and null issues.
Purpose of the Study:
- To address the limitations of CDMAs, specifically white noise amplification and deep nulls in directivity patterns.
- To develop a novel microphone array configuration that mitigates spatial aliasing effects.
Main Methods:
- Theoretical analysis identified zeros of the Bessel function as the cause of nulls in CDMAs.
- Developed a robust concentric circular differential microphone array (CCDMA) by combining microphone rings with optimized radii.
Main Results:
- The proposed CCDMA approach effectively mitigates both white noise amplification and deep nulls.
- Simulation results demonstrate the superiority of CCDMAs over traditional CDMAs and existing robust CDMAs.
Conclusions:
- CCDMAs provide a robust solution for improving directivity and noise performance in microphone arrays.
- The findings enable more practical and effective applications of differential microphone arrays in audio systems.
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