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In-Car Communication

  • Christian Lüke
  • Gerhard Schmidt
  • Anne Theiß
  • Jochen Withopf
Chapter

Abstract

Communicating inside a car can be difficult because there is usually a high level of background noise and also the talking and the listening passengers do not necessarily face each other as they would do in a natural conversation. In-car communication (ICC) systems are a solution to this problem. They record the talkers’ speech signal by means of microphones and reproduce it over loudspeakers that are located close to the listening passengers. However, such systems operate in a closed electroacoustic loop which significantly limits the gain that can be introduced by the system. In order to improve this gain margin and to achieve additional signal enhancement, several signal processing techniques are applied in ICC systems. Special care has to be taken about the signal delay: If it is too large, the reverberation inside the car is increased considerably and the speech reproduced over the loudspeakers might be perceived as an echo by the speaking passengers. In this chapter, an overview of the signal processing components of an ICC system is given. The necessary signal processing steps are explained and approaches to implement them are shown, especially with a focus on low processing delays.

Keywords

Echo cancellation Feedback In-car communication (ICC) Low-delay filter banks Noise reduction Speech intelligibility 

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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Christian Lüke
    • 1
  • Gerhard Schmidt
    • 1
  • Anne Theiß
    • 1
  • Jochen Withopf
    • 1
  1. 1.Digital Signal Processing and System TheoryChristian-Albrechts-Universität zu KielKielGermany

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