Automatic Evaluation of In-Car Communication Systems

In-car communication systems can improve the communication within a passenger compartment. To accomplish this, the speech signal of the talking passenger is recorded by the already installed hands-free microphones and played back via the loudspeakers located close to the listener. Further information about ICC systems can be found here.

After the implementation of an ICC system two main questions appear:

  • What does improve the communication for the passengers?
  • What does impair the communication for the passengers?

Due to the fact that at least two persons are involved in a conversation these two questions have to be answered for the listening and the talking passenger within in the passenger compartment.In addition, quality is a rather subjective concept, which depends on a variety of factors.

A first, intuitive approach to evaluate ICC systems would be to form a group of test subjects which have to evaluate the system in terms of speech-quality and speech-intelligibility. This evaluation can be perfomed by diagnostic, modified rhyme or comparison mean opinion score tests, so-called subjective test methods. These tests are quite expensive due to their duration and the large number of necessary subjects. To reduce costs and to produce more reliable and of course reproducible test results, objective tests are highly desirable.

Due to the fact, that the term quality is a complex concept, a sophisticated ICC system evaluation strategy is required. By our group a first concept consisting of three evaluation groups of different evaluation methods has been published (see literature hint below). Within each of these groups different measures should be utilized and combined to an overall quality result. First instrumental evaluation methods, such as the ICC system delay estimation, ICC system support, the signal-to-noise ratio (SNR) difference or spectral distance, have been published. All these mentioned evaluation methods do have in common, that they utilize a black-box testing, which allows the evaluation of an arbitrary ICC system.


Corresponding Publications

G. Schmidt, and A. Theiß: Automatic Evaluation of In-Car Communication Systems, Proc. DAGA, Kiel, Germany, open access, 2017

R. Landgraf, G. Schmidt, J. Köhler-Kaeß, O. Niebuhr, and T. John: More Noise, Less Talk - The Impact of Driving Noise and ICC Systems on Acoustic-prosodic Parameters in Dialogue, Proc. DAGA, Kiel, Germany, open access, 2017

A. Theiß, G. Schmidt: Spectral Distance Analysis for Quality Estimation of In-Car Communication Systems, 7th Biennial Workshop on DSP for In-Vehicle Systems and Safety 2015, Berkeley, CA, USA

R. Landgraf, O. Niebuhr, G. Schmidt, T. John, C. Lüke, A. Theiß: Von der Straße ins Labor: Die Modifikation der Sprachproduktion bei lauten Fahrgeräuschen, DAGA 2015, Nürnberg, Germany

S. Graf, A. Theiß, T. Herbig, G. Schmidt: Listening Test to Determine the Mismatch Between Signal-To-Noise Ratio and Human Perception, DAGA 2015, Nürnberg, Germany

C. Lüke, A. Wolf, M. Brodersen, G. Schmidt: Digitale Simulation der Fahrzeuginnenraumakustik zur Unterstützung der Entwicklung und Evaluierung von Innenraum-Kommunikationssystemen, DAGA 2015, Nürnberg, Germany

T. John, R. Landgraf, C. Lüke, S. Rohde, G. Schmidt, A. Theiß, J. Withopf: Über die Verbesserung der Sprachkommunikation in geräuschbehafteten Umgebungen, in O. Niebuhr (ed.): Formen des Nichtverstehens, Peter Lang, December 2014 (in German)

A. Theiß, G. Schmidt, J. Withopf, C. Lüke: Instrumental Evaluation of In-Car Communication Systems, Proc. ITG Fachtagung Sprachkommunikation 2014, Erlangen, Germany

A. Theiß, G. Schmidt: Investigation of Self-Masking Effects for the Evaluation of In-Car Communication Systems, Proc. International Workshop on Acoustic Signal Enhancement IWAENC 2014, Antibes, France

C. Lüke, G. Schmidt, A. Theiß, J. Withopf: In-Car Communication, in G. Schmidt, H. Abut, K. Takeda, J. Hansen (eds.), Smart Mobile In-Vehicle Systems, Springer, January 2014

T. John, O. Niebuhr, G. Schmidt and A. Theiß: Phonetic Analyses vs. Dirty Signals: Fixing the Paradox, Proc. ESSV, Bielefeld , Germany, 2013

C. Lüke, A. Theiß, G. Schmidt, O. Niebuhr, T. John: Creation of a Lombard Speech Database using an Acoustic Ambiance Simulation with Loudspeakers, 6th Biennial DSP Workshop for In-Vehicle Systems 2013, Seoul, Korea

G. Schmidt, A. Theiß, J. Withopf, A. Wolf: Evaluation of In-Car Communication Systems, in J. Hansen, P. Boyraz, K. Takeda, H. Abut (eds.), Digital Signal Processing for In-Vehicle Systems and Safety, Springer, January 2012

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


Website News

18.06.2017: Page about KiRAT news added (also visible in KiRAT).

31.05.2017: Some pictures added.

23.04.2017: Time line for the lecture "Adaptive Filters" added.

13.04.2017: List of PhD theses added.

Our Visitors

Today 3

Yesterday 5

Week 33

Month 103

All 642


Prof. Dr.-Ing. Gerhard Schmidt


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

Alexej Namenas - A New Guy in the Team

In June Alexej Namenas started in the DSS Team. He will work on real-time tracking algorithms for SONAR applications. Alexej has done both theses (Bachelor and Master) with us. The Bachelor thesis in audio processing (beamforming) and the Master thesis in the medical field (real-time electro- and magnetocardiography). In addition, he has intership erperience in SONAR processing.

We are pretty ...

Read more ...