Relationship between voice and autonomic responses in the state of neural fatigue

Abstract

  Fatigue reduces mental activity during the day and may induce mood swings, errors due to inattention, poor performance in overall behavior, and accidents due to falling asleep. In fatigue measurement, there is a need for a method that can measure fatigue immediately and easily each time it occurs. We have studied the detection of fatigue states from speech using chaos theory, but have been unable to determine the actual degree of fatigue or the degree of focus on the task. In this study, salivary amylase was measured as an objective index of fatigue, and LF/HF was measured from heart rate variability during the fatigue task, which was examined together with the results of voice analysis. As a result, the participants in the experiment objectively responded in a way that meant they were fatigued, and it was possible to infer this state from their speech.