An acoustic framework for detecting fatigue in speech based human-computer-interaction

Abstract

This article describes a general framework for detecting accident-prone fatigue states based on prosody, articulation and speech quality related speech characteristics. The advantages of this real-time measurement approach are that obtaining speech data is non obtrusive, and free from sensor application and calibration efforts. The main part of the feature computation is the combination of frame level based speech features and high level contour descriptors resulting in over 8,500 features per speech sample. In general the measurement process follows the speech adapted steps of pattern recognition: (a) recording speech, (b) preprocessing (segmenting speech units of interest), (c) feature computation (using perceptual and signal processing related features, as e.g. fundamental frequency, intensity, pause patterns, formants, cepstral coefficients), (d) dimensionality reduction (filter and wrapper based feature subset selection, (un-)supervised feature transformation), (e) classification (e.g. SVM, K-NN classifier), and (f) evaluation (e.g. 10-fold cross validation). The validity of this approach is briefly discussed by summarizing the empirical results of a sleep deprivation study. © 2008 Springer-Verlag Berlin Heidelberg.