Latest Talks

Jonas Sautter, Nuance Communications, Ulm, Germany

Details

  • Date: 20.11.2017
  • Time: 17:15 h
  • Place: Aquarium, Building D, Faculty of Engineering, Kaiserstr. 2., 24143 Kiel

 

Abstract

In mobile communication, the bandwidth of transferred speech signals is either narrow-band (300Hz – 3.4kHz) or wide-band (50Hz – 7kHz or higher). As the limitation to 3.4kHz degrades the speech quality and intelligibility, it is of great interest to artificially extend narrow-band speech signals to wide-band speech.

This talk presents a deep neural network (DNN) approach to artificial bandwidth extension with a focus on robustness in practical applications.

It is based on the source-filter model which decomposes the signal into two parts:

  • an excitation signal and
  • a spectral envelope.

The excitation (source part) describes the fine spectral structure which consists of white noise for unvoiced speech and an impulse train for voiced speech. The spectral envelope (filter part) describes the coarse spectral structure, i.e. the formants or resonance frequencies that make up different phonemes.

While the extension of the excitation signal can be done with simple mathematical methods that do not introduce strong artifacts, the envelope is much more relevant for the quality of the reconstructed wide-band signal. That is why the wide-band envelope is estimated with DNNs in this approach, which are trained on a large speech corpus.

 

Short biography

Jonas Sautter studied Electrical Engineering, Information Technology and Computer Engineering at RWTH Aachen University, Germany. He received his Master of Science degree in 2016. The Master’s thesis with the title “Digital Robust Control for Active Noise Cancellation in Headphones and Hearing Aids” was composed at the Institute of Communication Systems at RWTH Aachen. Since November 2016, he is a PhD student at Nuance Communications in Ulm, supervised by Professor Gerhard Schmidt, Head of the Digital Signal Processing and System Theory group at Christian-Albrechts-Universität, Kiel.

Prof. Dr. med. Wilhelm Schulte-Mattler, Neurologische Klinik und Poliklinik, Universität Regensburg

Details

  • Date: 14.09.2017
  • Time: 17:00 h
  • Place: Aquarium, Building D, Faculty of Engineering, Kaiserstr. 2., 24143 Kiel

 

German title

Physiologie peripherer Nerven aus Sicht der Signalverarbeitung

 

Abstract

To transmit information, peripheral nerve fibers locally change their electrical membrane properties. The changed regions move along the fibers causing traveling electrical fields, causing changes in voltage over time that depend both on where the voltage is recorded and on the nerve’s properties. Things are complicated by the nerves being composed of many thousands of fibers.

A simple model that explains these voltage changes, namely the signals that are recorded from actively transmitting nerves, will be presented. These signals provide information about the nerve’s function. Both, the influence of the recording conditions and the influence of various nerve disorders on the recorded waveforms will be presented. The usefulness of simple measures, such as amplitude and duration, is established. More advanced signal analysis indeed provides more information about peripheral nerve disorders.

 

Short biography

Wilhelm Schulte-Mattler studied Mathematics and Physics, followed by Medicine. He graduated at the University of Würzburg in 1988. His thesis was on Quantification of recruitment in needle-EMG. He specialized in Neurology in 1993. After heading Clinical Neurophysiology in the Dept. of Neurology, University of Halle-Wittenberg; since the year 2000, he is head of Clinical Neurophysiology in the Dept. of Neurology, University of Regensburg. A significant part of his work is on waveform analysis in clinical neurophysiology, particularly in electromyography and in electroneurography.

Ingo Schalk-Schupp, Nuance Communications, Ulm, Germany

Details

  • Date: 10.04.2017
  • Time: 17:15 h
  • Place: Aquarium, Building D, Faculty of Engineering, Kaiserstr. 2., 24143 Kiel

 

Abstract

This presentation provides a short overview concerning acoustic echo cancellation and acoustic echo suppression methods followed by a more in-depth discussion of new methods dealing with Hammerstein-type nonlinear distortions.

The Hammerstein system is divided into a linear and a parallel nonlinear part by an alternative way to define of the linear one. The implications of this separation definition and its relation to linear acoustic echo cancellation are illuminated.

Based on this approach, and assuming a converged linear echo canceller, a suppression approach for nonlinearly distorted acoustic echo signal components is introduced, the essential component of which is the nonlinear echo power spectral density estimation, which depends on one unknown real scalar parameter.

Subsequently, an identification algorithm for said parameter is presented, which results in a usable nonlinear echo suppressor still under the assumption of a converged linear echo canceller. Moreover, a generic comprehensive evaluation method for suppressor-type algorithms is advertised.

Finally, the challenge of concurrently adaptive linear echo canceller and nonlinear echo suppressor is analyzed and a solution for a full system is presented. After listening to several audio examples, the audience is invited to discuss the presentation’s contents.

 

Short biography

Ingo Schalk-Schupp studied systems engineering and technical cybernetics at Otto von Guericke University in Magdeburg, Germany. He graduated as a diploma engineer (Diplomingenieur) in 2012 with a diploma thesis titled “Speech Signal Enhancement in Automotive Environments” composed at Nuance Communications in Ulm, Germany. The thesis comprised two patent applications and was granted the best thesis award by the “Magdeburger Kybernetiker e.V.” Since 2012, he has been a PhD student with Nuance in Ulm and is supervised by Professor Andreas Wendemuth, Chair of Cognitive Systems at Otto von Guericke University Magdeburg. This presentation reflects the author’s findings from his PhD research.

Dr. Akihiko (Ken) Sugiyama

Details

  • Date: 06.12.2016
  • Time: 17:15 h
  • Place: Aquarium, Building D, Faculty of Engineering, Kaiserstr. 2., 24143 Kiel

 

Abstract

This lecture presents the 25-year history of audio coding technology. Focusing on MPEG Audio Coding that is the most widely used international standard in our daily life, some im-portant techniques we contributed are explained along the history. Recent standardization activities are briefly touched to show the unlimited potential of audio coding. An encounter of the Silicon Audio, developed in 1994 and the real ancestor of iPod, is the highlight of this lecture, which cannot be experienced elsewhere. The audience will see how iPod started its function 20 years ago.

 

Short biography

Akihiko Sugiyama (a.k.a. Ken Sugiyama), affiliated with NEC Data Science Research Labs., has been engaged in a wide variety of research projects in signal processing such as audio coding and interference/noise control. His team developed the world's first Silicon Audio in 1994, the ancestor of iPod. He served as Chair of Audio and Acoustic Signal Processing Tech. Committee, IEEE Signal Processing Society (SPS) [2011-2012], as associate editors for several jour-nals such as IEEE Trans. SP [1994-1996], as the Secretary and a Member at Large to the Con-ference Board of SPS [2010-2011], as a member of the Awards Board of SPS [2015], and as the Chair of Japan Chapter of SPS [2010-2011]. He was a Technical Program Chair for ICASSP2012. He has contributed to 16 chapters of books and is the inventor of over 150 registered patents with more pending applications in the field of signal processing in Japan and overseas. He received 13 awards such as the 2002 IEICE Best Paper Award, the 2006 IEICE Achievement Award, and the 2013 Ichimura Industry Award. He is Fellow of IEEE and IEICE, and a Distinguished Lecturer in 2014 and 2015 for IEEE SPS. He is also known as a big host for a total of over 70 internship students.

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13.08.2017: New Gas e.V. sections (e.g. pictures or prices) added.

05.08.2017: The first "slide carousel" added.

03.08.2017: Started with the RED project. Will be ready in a few years ...

30.07.2017: List of PhD theses updated and extended.

Recent Publications

P. Durdaut, J. Reermann, S. Zabel, Ch. Kirchhof, E. Quandt, F. Faupel, G. Schmidt, R. Knöchel, and M. Höft: Modeling and Analysis of Noise Sources for Thin-Film Magnetoelectric Sensors Based on the Delta-E Effect, IEEE Transactions on Instrumentation and Measurement, published online, 2017

P. Durdaut, S. Salzer, J. Reermann, V. Röbisch, J. McCord, D. Meyners, E. Quandt, G. Schmidt, R. Knöchel, and M. Höft: Improved Magnetic Frequency Conversion Approach for Magnetoelectric Sensors, IEEE Sensors Letters, published online, 2017

 

Contact

Prof. Dr.-Ing. Gerhard Schmidt

E-Mail: gus@tf.uni-kiel.de

Christian-Albrechts-Universität zu Kiel
Faculty of Engineering
Institute for Electrical Engineering and Information Engineering
Digital Signal Processing and System Theory

Kaiserstr. 2
24143 Kiel, Germany

Recent News

Jens Reermann Defended his Dissertation with Distinction

On Friday, 21st of June, Jens Reermann defended his research on signals processing for magnetoelectric sensor systems very successfully. After 90 minutes of talk and question time he finished his PhD with distinction. Congratulations, Jens, from the entire DSS team.

Jens worked for about three and a half years - as part of the collaborative research center (SFB) 1261 - on all kinds of signal ...


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