Abstract
In 1998, it was discovered that the chaotic characteristics of uttered voice change according to the psychosomatic condition of a speaker. The development of a fatigue and drowsiness predictor for automobile drivers and airplane pilots was then started at ENRI. This predictor could estimate drivers and pilots' probability of occurrence of drowse from their voice. It was developed as an application of digital signal processing based on the theory of chaos, and was designed to work in real time. As the results of experiments for evaluation of the predictor carried out since the discovery, the authors believe that it would be possible to evaluate the mental and physical condition of critical workers in real-time in their working environments by monitoring only their speech. We would like to propose the top stream of preventive safety system that has full compatibility with any other driving safety system for cars and trucks drivers.
Keywords: Human Voice, Fatigue, Chaos Theory and Driving Simulator.