APSIPA Transactions on Signal and Information Processing > Vol 12 > Issue 3

Wavelength-Proportional Interpolation and Extrapolation of Virtual Microphone for Underdetermined Speech Enhancement

Ryoga Jinzai, University of Tsukuba, Japan, Kouei Yamaoka, University of Tsukuba and Tokyo Metropolitan University, Japan, Shoji Makino, University of Tsukuba and Waseda University, Japan, s.makino@ieee.org , Nobutaka Ono, Tokyo Metropolitan University, Japan, Mitsuo Matsumoto, University of Tsukuba, Japan, Takeshi Yamada, University of Tsukuba, Japan
 
Suggested Citation
Ryoga Jinzai, Kouei Yamaoka, Shoji Makino, Nobutaka Ono, Mitsuo Matsumoto and Takeshi Yamada (2023), "Wavelength-Proportional Interpolation and Extrapolation of Virtual Microphone for Underdetermined Speech Enhancement", APSIPA Transactions on Signal and Information Processing: Vol. 12: No. 3, e21. http://dx.doi.org/10.1561/116.00000078

Publication Date: 13 Jul 2023
© 2023 R. Jinzai, K. Yamaoka, S. Makino, N. Ono, M. Matsumoto and T. Yamada
 
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In this article:
Introduction 
Virtual Microphone Technique 
Wavelength-Proportional Virtual Microphone 
Maximum SNR Beamformer 
Experiment 
Conclusion 
References 

Abstract

We previously proposed the virtual microphone technique to improve speech enhancement performance in underdetermined situations, in which the number of channels is virtually increased by estimating extra microphone signals at arbitrary positions along the straight line formed by real microphones. The effectiveness of the interpolation of virtual microphone signals for speech enhancement was experimentally confirmed. In this work, we apply the extrapolation of a virtual microphone as preprocessing of the maximum signal-to-noise ratio (SNR) beamformer and compare its speech enhancement performance (the signal-to-distortion ratio (SDR) and signal-to-interference ratio (SIR)) with that of using the interpolation of a virtual microphone. Furthermore, we aim to improve speech enhancement performance by solving a trade-off relationship between performance at low and high frequencies, which can be controlled by adjusting the virtual microphone interval. We propose a new arrangement where a virtual microphone is placed at a distance from the reference real microphone proportional to the wavelength at each frequency. From the results of our experiment in an underdetermined situation, we confirmed speech enhancement performance using the extrapolation of a virtual microphone is higher than that of using the interpolation of a virtual microphone. Moreover, the proposed wavelength-proportional interpolation and extrapolation method improves speech enhancement performance compared with the interpolation and extrapolation. Furthermore, we present the directivity patterns of a spatial filter and confirmed the behavior that improves speech enhancement performance.

DOI:10.1561/116.00000078

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APSIPA Transactions on Signal and Information Processing Special Issue - Advanced Acoustic, Sound and Audio Processing Techniques and Their Applications
See the other articles that are part of this special issue.