@InProceedings{Bulling2018_383,
author = {Philipp Bulling and Klaus Linhard and Arthur Wolf and Gerhard Schmidt},
booktitle = {Studientexte zur Sprachkommunikation: Elektronische Sprachsignalverarbeitung 2018},
title = {Automatic Equalization for In-Car Communication Systems},
year = {2018},
editor = {André Berton and Udo Haiber and Wolfgang Minker},
month = mar,
pages = {7--14},
publisher = {TUDpress, Dresden},
abstract = {An automatic equalization filter for in-car communication (ICC) systems
is presented. ICC systems usually use an adaptive filter to stabilize the feedback
loop between the loudspeakers and the speaker microphone. In this work, a second
adaptive filter is introduced that aims at equalizing the sound, radiated from
one or more loudspeakers, at the listener’s position in order to achieve a linear frequency
response. Therefore, a microphone is placed close to the listener’s ears in
the car ceiling. To obtain a flat frequency response at the listener’s position, the
loudspeaker signal must be equalized with the inverse frequency response of the
path between the loudspeakers and the microphone. This path is described by the
impulse response and it is estimated by means of an adaptive filter in this work. To
design the equalization filter, the frequency response of the adaptive filter is used.
Target applications are speech applications operating in a closed electro-acoustic
loop, such as ICC systems. However, the idea can also be applied to other audio
presentations. Both simulations and tests in a real car show that the proposed automatic
equalization filter improves speech quality in terms of a natural sounding
system.},
isbn = {978-3-959081-28-3},
issn = {0940-6832},
keywords = {Signal Processing},
url = {https://www.essv.de/pdf/pdf/2018_7_14.pdf},
}