Predavanje "Digital Signal...
Odjel za obradu signala Hrvatske sekcije IEEE poziva Vas na predavanje pod naslovom:

    “Digital Signal Processing of Audio Signals”

koje će održati profesor Douglas M. Chabries, Brigham Young University, SAD, u četvrtak, 22. veljače u 11:15 sati u Knjižnici Zavoda za elektroničke sustave i obradu informacija (zgrada D, 1. kat), na FER-u. Predavanje će biti na engleskom jeziku u trajanju od oko 45 minuta.

U opširnijoj obavijesti se nalazi biografija predavača i sažetak predavanja.

Digital signal processing has been applied to a variety of signal types. In this presentation, material will be presented to describe homomorphic digital signal processing techniques which were originally used to restore old sound recordings. Audio demonstrations will be presented of the recorded voice of Enrique Caruso before and after restoration, and then again after the orchestra is electronically removed by digital signal processing techniques. These established techniques will then be modified and applied to the problem of designing a digital hearing aid guided by the physiological characteristics of the human hearing system. Results will be presented for application of digital signal processing techniques to show the improvement available through using a multiplicative AGC (automatic gain control), directional noise suppression and adaptive noise suppression. These techniques are now being implemented in newly released digital hearing aids.

Short Biography

NAME: Douglas M. Chabries

TITLE: Dean Emeritus, Ira A Fulton College of Engineering and Technology


Ph.D. Brown University, Providence, Rhode Island, 1970
M.S.E.E. California Institute of Technology, Pasadena, CA, 1967
B.S.E.E. University of Utah, Salt Lake City, UT, 1966


Primary emphasis is in electrical engineering with extensive background in research and development of signal processing systems and algo¬rithms, especially in the areas of acoustics, image and adaptive processing. Experience in the areas of human image perception and human auditory perception. Served as Chairman for IEEE ASSP workshop session in 1986 and selected as session chairman for IEEE/ICASSP 88. Participated with the National Academy of Science panel on noise suppression for improvement of speech intelligibility. Understanding and experience in the area of underwater acoustic environment, computer simulation and computer simulation architecture, system analysis including guidance and control and signal processing, investigation of acoustics, and analysis of scattering. Published several articles on acoustic scattering, adaptive signal processing, speech processing, synthetic aperture radar and image processing. Recent work includes the application of multi-spectral imaging to ancient texts including the Petra and Herculaneum scrolls.

Jan 1995 to Jan 2005 Dean, College of Engineering and Technology

Aug 1990 to Jan 1995 Assistant Academic Vice President, Brigham Young University. Responsible for the planning and coordination of computing systems, networks and digital communications on the BYU campus.

September 1983 to 1990 Chairman, Department of Electrical and Computer Engineering, Brigham Young University. Advanced in rank to Professor in 1984.

September 1, 1978 to 1983 Associate Professor of Electrical and Computer Engineer¬ing Department, Brigham Young University. Responsible for teaching under¬graduate and graduate level courses in digital signal processing and pattern recognition.


NDEA Title IV Fellowship, NUC Work Study Fellowship, Member of Eta Kappa Nu Honor Society, Member of Tau Beta Pi Honor Society, Member of Sigma Xi Honor Society, and Member of Phi Kappa Phi Honor Society, Awarded the Governors Science Medal- State of Utah, 1988, Received the BYU Blue Key Faculty of the Month Award, 1985, Received the BYU Outstanding College Faculty Award, College of Engineering and Technology, 1988, Received the BYU Sponsored Research Achievement Award, Office of Technology Transfer, 1990. Received the UEES Pathfinder Award 2002.


1. J. M. McCool, B. Widrow, J. Zeidler, R. Hearn, D. M. Chabries, "Adaptive line enhancer," US Patent 4,238,746, 9 Dec 1980.

2. B. Widrow, J. M. McCool, R. Hearn, J. Zeidler, D. M. Chabries, "Adaptive Noise Cancelling," filed as a classified patent, US Patent Office.

3. J. M. McCool, B. Widrow, R. Hearn, J. Zeidler, D. M. Chabries, R. Moore, "Adaptive Detector, " US Patent 4,243,935, 6 Jan. 1981.

4. B. Widrow, J. M. McCool, R. Hearn, J. Zeidler, D. M. Chabries,. "ALICE" Adaptive Line Cancelling and Enhancing, filed as a classified patent, US Patent Office.

5. D. M. Chabries and R. W. Christiansen, "Still frame audio on video disc," filed with US Patent Office by WICAT and abandoned.

6. D. M. Chabries, R. W. Christiansen, D. Lynn, and G. Kenworthy, "Adaptive Noise Suppressor," 10 October 1985. US Patent 4,658,426.

7. D. M. Chabries, "Data Compression Method and Apparatus for Radar Image Formation," Document Disclosure No. 187,369, US Patent Office, U. S. Patent 4,872,012 issued October 3, 1989.

8. D. M. Chabries, R. W. Christiansen, Method and Apparatus for Processing Sampled Data Signals by Utilizing Preconvolved Quantized Vectors, 20 December 11, 1990, Disclosure Document No. 164915, U.S. Patent Office, U.S. Patent 4,977,604.

9. Chabries, D. M., R. H. Brey, M. S. Robinette, R. W. Christiansen, and G. R. Kenworthy, "Digital Hearing Enhancement Apparatus," 2 July 1991. US Patent 5,029,217.

10. Richard Frost, Chris Barnes, D. M. Chabries, and R. W. Christiansen, " System and Method For Data Compression Using Multiple Codewords and Transmitted Indices," US Patent 5,250,949, 5 Oct. 1993.

11. T. G. Stockham, Jr. and D. M. Chabries, "Hearing Aid Device Incorporating Signal Processing Techniques, 19 March 1996, US Patent 5,500,902.

12. T. G. Stockham, Jr. and D. M. Chabries, “Hearing Aid Device Incorporating Signal Processing Techniques, 8 December 1998, US Patent 5,848,171.

13. Carver Mead, D. M. Chabries and Keith Davis, “A Digital Hearing Aid Using Differential Signal Representations,” 28 March 2000, US Patent 6,044,162.

14. Keith Davis, X. Fang, Darrell Rose, and Douglas M. Chabries, “Hearing Aid Fitting System,” 3 June 2003, US Patent 6,574,342.

15. Douglas M. Chabries, C. Mead, R. W. Christiansen, K. Davis, X Fang and William C. Borough, “A High Fidelity Digital Hearing Aid with Noise Suppression,” submitted to the US Patent Office November 1999.

16. Douglas M. Chabries, R. W. Chrisitiansen, A. M. Hammon and W. C. Borough, “Hearing Aid Device Incorporating Signal Processing Techniques,” 26 April 2005, US Patent 6,885,752.
Autor: Sven Lončarić
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