Abstract
This chapter presents arrays with two microphones and a postfilter for noise reduction and acoustic echo cancellation. The postfilter algorithm exploits the spatial coherence of the microphone signals. In contrast to single-microphone enhancement algorithms, it does not need an explicit noise power spectral density estimate. An analysis of the mean square error reveals that the coherence properties of the microphone signals are of paramount importance for the performance of the postfilter. Coherence measurements of signals in various acoustic environments are presented. The influence of the directivity and orientation of the microphones on the measured coherence is discussed and rules for the design of the acoustic interface are given. Finally, applications of this approach are presented. The two-microphone algorithm is employed to reduce the non-stationary noise in the voice intercom of a computed tomography scanner. It is also combined with echo cancellers to be used in a robust desktop conferencing device.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
B. Widrow, J.R. Glover, J.M. McCool, et al., “Adaptive Noise Cancelling: Principles and Applications,” in Proc. IEEE, vol. 63, no. 12, pp. 1692–1716, 1975.
W. Armbruster, R. Czarnach, and P. Vary, “Adaptive Noise Cancellation with Reference Input - Possible Applications and Theoretical Limits,” in Signal Processing III, Theories and Applications, pp. 391–394, Elsevier, 1986.
J.B. Allen, D.A. Berkley, and J. Blauert, “Multimicrophone Signal-Processing Technique to Remove Room Reverberation from Speech Signals,” J. Acoust. Soc. Am., vol. 62, no. 4, pp. 912–915, 1977.
E.R. Ferrara and B. Widrow, “Multichannel Adaptive Filtering for Signal Enhancement,” IEEE Trans. Acoustics, Speech, Signal Processing, vol. ASSP-29, no. 3, pp. 766–770, 1981.
R. Le Bouquin and G. Faucon, “On Using the Coherence Function for Noise Reduction,” in Signal Processing V: Theories and Applications, pp. 1103–1106, Elsevier, 1990.
R. Le Bouquin and G. Faucon, “Study of a noise cancellation system based on the coherence function,” in Signal Processing VI: Theories and Applications, pp. 1633–1636, Elsevier, 1992.
R. Martin and P. Vary, “A Symmetric Two Microphone Speech Enhancement System - Theoretical Limits and Application in a Car Environment,” in Proc. Fifth IEEE Signal Processing Workshop, pp. 4.5.1–4.5. 2, 1992.
R. Martin and P. Vary, “Combined Acoustic Echo Cancellation, Dereverberation, and Noise Reduction: A Two Microphone Approach,” in Proc. Third Int. Workshop on Acoustic Echo Control, Lannion, France, pp. 125–132, 1993.
R. Zelinski, “A Microphone Array with Adaptive Post-Filtering for Noise Reduction in Reverberant Rooms,” in Proc. IEEE Int. Conf. Acoust., Speech, Signal Processing (ICASSP-88), New York NY, USA, pp. 2578–2581, Apr. 1988.
R. Zelinski, “Noise Reduction Based on Microphone Array with LMS Adaptive Post-Filtering,” Elect. Lett., vol. 26, no. 24, pp. 2036–2037, 1990.
C. Marro, Y. Mahieux, and K U Simmer, “Analysis of Noise Reduction and Dereverberation Techniques Based on Microphone Arrays with Postfiltering,” IEEE Trans. SAP, vol. 6, no. 3, pp. 240–259, 1998.
J.S. Bendat and A.G. Piersol, Measurement and Analysis of Random Data, Wiley, 1966.
G.C. Carter, “Coherence and Time Delay Estimation,” in Proc. IEEE, vol. 75, no. 2, pp. 236–255, 1987.
H. Kuttruff, Room Acoustics, Elsevier Science, 3rd edn., 1990.
B.F. Cron and C.H. Sherman, “Spatial-Correlation Functions for Various Noise Models,” J. Acoust. Soc. Am., vol. 34, no. 11, pp. 1732–1736, 1962.
P. Dämmig, “Zur Messung der Diffusität von Schallfeldern durch Korrelation,” Acustica, vol. 7, pp. 387, 1957.
R. Martin, “Hands-free Telephones based on Multi-Microphone Echo Cancellation and Noise Reduction,” PhD Thesis (in German), Institute of Communication Systems and Data Processing, Aachen University of Technology, Aachen, Germany, 1995.
T. Kailath, Lectures on Wiener and Kalman Filtering, CISM Courses and Lectures No. 140, Springer Verlag, 1981.
R. Martin, “An Efficient Algorithm to Estimate the Instantaneous SNR of Speech Signals,” in Proc. EUROSPEECH, Berlin, Germany, pp. 1093–1096, 1993.
C.F.N. Cowan and P.M. Grant, Adaptive Filters, Prentice Hall, 1985.
J.F. Kaiser, “Nonrecursive Digital Filter Design Using the Io-sinh Window Function,” in Proc. IEEE Int. Symp. on Circuits and Syst., pp. 20–23, 1974.
R. Le Bouquin, G. Faucon, and A. Akbari Azirani, “Proposal of a Composite Measure for the Evaluation of Noise Cancelling Methods in Speech Processing,” in Proc. EUROSPEECH, Berlin, Germany, pp. 227–230, 1993.
M. Dörbecker and S. Ernst, “Combination of Two-Channel Spectral Subtraction and Adaptive Wiener Post-Filtering for Noise Reduction and Dereverberation,” in Proc. EUSIPCO, Trieste, Italy, pp. 995–998, 1996.
M. Dörbecker, Multi-channel Algorithms for the Enhancement of Noisy Speech for Hearing Aids, PhD Thesis (in German), Institute of Communication Systems and Data Processing, Aachen University of Technology, Aachen, Germany, 1998.
C. Breining, P. Dreiseitel, E. Hänsler, et al., “Acoustic Echo Control. An application of very high order adaptive filters,” IEEE Signal Processing Mag, vol. 16, no. 4, pp. 42–69, 1999.
S.L. Gay, J. Benesty (eds.),Acoustic Signal Processing for Telecommunication, Kluwer, 2000.
E. Hänsler, “The Hands-Free Telephone Problem–An Annotated Bibliography,” Signal Processing, vol. 27, pp. 259–271, 1992.
E. Hänsler, “The Hands-Free Telephone Problem–An Annotate Bibliography Update,” Annales des Télécommunication, vol. 49, no. 7–8, pp. 360–367, 1994.
J.R. Deller, J.G. Proakis, and J.H.L. Hansen, Discrete-Time Processing of Speech Signals, Macmillan, 1993.
Y. Ephraim, “Statistical-Model-Based Speech Enhancement Systems,” Proc. IEEE, vol. 80, no. 10, pp. 1526–1555, 1992.
Y. Grenier, M. Xu, J. Prado, and D. Liebenguth, “Real-Time Implementation of an Acoustic Antenna for Audioconferencing,” in 1st Intl. Workshop on Acoustic Echo Control, Berlin, Germany, 1989.
R. Martin and P. Vary, “Combined Acoustic Echo Cancellation, Dereverberation, and Noise Reduction: A Two Microphone Approach,” Annales des Télécommunications, vol. 49, no. 7–8, pp. 429–438, 1994.
B. Ayad and G. Faucon, “Acoustic Echo and Noise Cancelling for Hands-Free Communication Systems,” in Proc. Fourth Int. Workshop on Acoustic Echo and Noise Control, ROros, Norway, pp. 91–94, 1995.
G. Faucon and R. Le Bouquin Jeannes, “Joint System for Acoustic Echo Cancellation and Noise Reduction,” in Proc. EUROSPEECH, Madrid, Spain, pp. 15251528, 1995.
R. Martin and J. Altenhöner, “Coupled Adaptive Filters for Acoustic Echo Control and Noise Reduction,” in Proc. Int. Conf. Acoust., Speech, Signal Processing (ICASSP-95), Detroit MI, USA, pp. 3043–3046, May 1995.
R. Martin and P. Vary, “Combined Acoustic Echo Control and Noise Reduction for Hands-Free Telephony–State of the Art and Perspectives,” in Proc. EUSIPCO, Trieste, Italy, pp. 1107–1110, 1996.
R. Martin and S. Gustafsson, “The Echo Shaping Approach to Acoustic Echo Control,” Speech Communication, vol. 20, pp. 181–190, 1996.
W. Herbordt and W. Kellermann, “GSAEC - Acoustic Echo Cancellation Embedded into the Generalized Sidelobe Canceller,” in Proc. EUSIPCO, Tampere, Finland, 2000.
W. Kellermann, “Strategies for Combining Acoustic Echo Cancellation and Adaptive Beamforming Microphone Arrays,” in Proc. Int. Conf. Acoust., Speech, Signal Processing (ICASSP-97), Munich, Germany, pp. 219–222, 1997.
R. Martin, S. Gustafsson, and M. Moser, “Acoustic Echo Cancellation for Microphone Arrays Using Switched Coefficient Vectors,” in Proc. 5th Intl. Workshop on Acoustic Echo and Noise Control (IWAENC), London, England, pp. 85–88, 1997.
W. Kellermann, “Some Properties of Echo Path Impulse Responses of Microphone Arrays and Consequences for Acoustic Echo Cancellation,” in Proc. Fourth Int. Workshop on Acoustic Echo and Noise Control, Roros, Norway, pp. 39–43, 1995.
C. Antweiler, Orthogonalizing Algorithms for Digital Compensation of Acoustic Echoes. PhD Thesis (in German), Institute of Communication Systems and Data Processing, Aachen University of Technology, Aachen, Germany, 1995.
M. Dörbecker, “Small Microphone Arrays with Optimized Directivity for Speech Enhancement,” in Proc. EUROSPEECH, Rhodes, Greece, pp. 327–330, 1997.
ITU-T Recommendation P.34, Transmission Characteristics of Hands-Free Telephones, Melbourne, Australia, 1988.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2001 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Martin, R. (2001). Small Microphone Arrays with Postfilters for Noise and Acoustic Echo Reduction. In: Brandstein, M., Ward, D. (eds) Microphone Arrays. Digital Signal Processing. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-04619-7_12
Download citation
DOI: https://doi.org/10.1007/978-3-662-04619-7_12
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-07547-6
Online ISBN: 978-3-662-04619-7
eBook Packages: Springer Book Archive