[The effect of hypoxia and mental stress on the distribution of energy in the phoneme "A"].

Considering the fact that one of the indicators of effects of hypoxia in pilots could be an altered speech we have analysed changes in uttering a sound (A) in our examinees, pilot-students, aged 21-23, under effects of hypoxia only, the associated effects of hypoxia and mental loading and under conditions of normal barometric pressure. In the frequency and three dimensional representation of the selected sound, there have been analysed frequency components, intensity, duration and quality of the sound. It has been found that acute hypoxia causes deep structural and durational changes.