tailieunhanh - Báo cáo hóa học: " Using Intermicrophone Correlation to Detect Speech in Spatially Separated Noise"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Using Intermicrophone Correlation to Detect Speech in Spatially Separated Noise | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 93920 Pages 1-14 DOI ASP 2006 93920 Using Intermicrophone Correlation to Detect Speech in Spatially Separated Noise Ashish Koul1 and Julie E. Greenberg2 1 Broadband Video Compression Group Broadcom Corporation Andover MA 01810 USA 2 Massachusetts Institute of Technology 77 Massachusetts Avenue Room E25-518 Cambridge MA 02139-4307 USA Received 29 April 2004 Revised 20 April 2005 Accepted 25 April 2005 This paper describes a system for determining intervals of high and low signal-to-noise ratios when the desired signal and interfering noise arise from distinct spatial regions. The correlation coefficient between two microphone signals serves as the decision variable in a hypothesis test. The system has three parameters center frequency and bandwidth of the bandpass filter that prefilters the microphone signals and threshold for the decision variable. Conditional probability density functions of the intermicrophone correlation coefficient are derived for a simple signal scenario. This theoretical analysis provides insight into optimal selection of system parameters. Results of simulations using white Gaussian noise sources are in close agreement with the theoretical results. Results of more realistic simulations using speech sources follow the same general trends and illustrate the performance achievable in practical situations. The system is suitable for use with two microphones in mild-to-moderate reverberation as a component of noise-reduction algorithms that require detecting intervals when a desired signal is weak or absent. Copyright 2006 A. Koul and J. E. Greenberg. 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. 1. INTRODUCTION Conventional hearing aids do not selectively attenuate background .