Latest Talks

Dr.-Ing. Vasudev Kandade Rajan, Becker Automotive Systems GmbH, Straubing, Germany

Details

  • Date: 27.11.2017
  • Time: 17:15 h
  • Place: Aquarium, Building D, Faculty of Engineering, Kaiserstr. 2., 24143 Kiel

 

Abstract

The application of active noise cancellation in real-world has not been fully realized yet. From reducing environment noise through the usage of headphones, to engine noise on commercial jets there are a number of use cases. Each of these use case brings its own set of challenges which can be understood only through multi-disciplinary work. One such use case the the reduction of road noise in vehicles. Structure-borne road noise dominates the cabin of modern vehicles. Several road noise cancellation (RNC) prototype systems have been implemented and demonstrated. These systems are based mainly on analog sensors. The placement of these sensors has been so far been based on random optimization methods. In this talk I will talk about the challenges in developing a generic digital RNC system which includes problem analysis, sensor placement, and performance. An adaptive algorithm process the acceleration signals with high convergence and reaction time for various speed and surface ranges, in order to maintain high audible effects for the passengers. Several modern vehicle platforms are integrated with the digital RNC system with ANC microphone at the headliners and the standard audio loudspeaker setup in order to integrate the technology with the existing audio layout of the vehicle.

 

Short biography

Vasudev Kandade Rajan received Bachelors degree in Electronics and Communication from Visvesvaraya Technological University, Bangalore, India. He joined as Project Research Assistant in July 2008 in the Electrical Communication Engineering Dept, Indian Institute of Science, Bangalore. There he worked on performance management of IEEE 802.11 WLANs until Sept 2009. He then went to obtain his Masters degree (MSc.) in Digital Communications, 2011 and PhD degree in Signal Processing, 2017 from Universtiy of Kiel, Germany. Currently he is working in the R&D department of Harman Becker Automotive Systems GmbH, Straubing, Germany.

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.

Website News

01.10.2017: Started with a Tips and Tricks section for KiRAT.

01.10.2017: Talks from Jonas Sauter (Nuance) and Vasudev Kandade Rajan (Harman/Samsung) added.

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

05.08.2017: The first "slide carousel" added.

Recent Publications

J. Reermann, P. Durdaut, S. Salzer, T. Demming,A. Piorra, E. Quandt, N. Frey, M. Höft, and G. Schmidt: Evaluation of Magnetoelectric Sensor Systems for Cardiological Applications, Measurement (Elsevier), ISSN 0263-2241, https://doi.org/10.1016/j.measurement.2017.09.047, 2017

S. Graf, T. Herbig, M. Buck, G. Schmidt: Low-Complexity Pitch Estimation Based on Phase Differences Between Low-Resolution Spectra, Proc. Interspeech, pp. 2316 -2320, 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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