Mathematical Problems in Engineering
Volume 2010 (2010), Article ID 371782, 12 pages
Research Article

The Application of Nonlinear Spectral Subtraction Method on Millimeter Wave Conducted Speech Enhancement

1Department of Biomedical Engineering, The Fourth Military Medical University, Xi'an 710032, China
2The Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China

Received 27 January 2010; Accepted 17 March 2010

Academic Editor: Massimo Scalia

Copyright © 2010 Sheng Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A nonlinear multiband spectral subtraction method is investigated in this study to reduce the colored electronic noise in millimeter wave (MMW) radar conducted speech. Because the over-subtraction factor of each Bark frequency band can be adaptively adjusted, the nonuniform effects of colored noise in the spectrum of the MMW radar speech can be taken into account in the enhancement process. Both the results of the time-frequency distribution analysis and perceptual evaluation test suggest that a better whole-frequency noise reduction effect is obtained, and the perceptually annoying musical noise was efficiently reduced, with little distortion to speech information as compared to the other standard speech enhancement algorithm.