Abstract
The physiological and psychological responses of vertical vibrations, from 0.2 to 2Hz, on human bodies were investigated. For physiological responses, the heart rate, the respiratory rate, the quantity of saliva secretion and the balance test were used as indices. For psychological responses, relationships between vibrational magnitude and feeling were determined by the semantic differential (SD) method.
The results obtained were; (1) exposures to low frequency vibrations decreased the heart rate, the respiratory rate and the quantity of saliva secretion, (2) the balance test indicated significant time decreases in standing upright on one leg with eyes closed with vibrations of 0.8Hz and lower, (3) factor analysis on data obtained by the SD method extracted factor of dynamism, and this factor strongly correlated with corresponding vibration acceleration levels, and (4) correlations were found between physiological and psychological responses. From these findings, the effects of low frequency vibrations on the body should be evaluated more objectively by adding psychological measurements to physiological ones.
