Open Access

Formant Frequencies under Cognitive Load: Effects and Classification

  • Tet Fei Yap1, 2Email author,
  • Julien Epps1, 2,
  • Eliathamby Ambikairajah1, 2 and
  • Eric H. C. Choi (EURASIP Member)2
EURASIP Journal on Advances in Signal Processing20102011:219253

Received: 1 August 2010

Accepted: 20 December 2010

Published: 26 December 2010


Cognitive load measurement systems measure the mental demand experienced by human while performing a cognitive task, which is useful in monitoring and enhancing task performance. Various speech-based systems have been proposed for cognitive load classification, but the effect of cognitive load on the speech production system is still not well understood. In this work, we study formant frequencies under different load conditions and utilize formant frequency-based features for automatic cognitive load classification. We find that the slope, dispersion, and duration of vowel formant trajectories exhibit changes under different load conditions; slope and duration are found to be useful features in vowel-based classification. Additionally, 2-class and 3-class utterance-based classification results, evaluated on two different databases, show that the performance of frame-based formant features was comparable, if not better than, baseline MFCC features.

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Authors’ Affiliations

School of Electrical Engineering and Telecommunications, The University of New South Wales
ATP Research Laboratory, National ICT Australia (NICTA)


© Tet Fei Yap et al. 2011

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.