[The effect on man of weak-intensity acoustic signals]

Studies have been made of the effect of weak clicks, click series, wide band noise with the intensity of 10-20 dB on healthy subjects. Changes in the activity of central mechanisms of perception were evaluated by long-latent auditory evoked potentials, changes in vegetative functions of the organism were checked by analysis of the periodic structure of cardiac activity. It was shown that weak acoustic stimuli exert relatively weak direct influence on the auditory system which is revealed as weak and unstable realization of the stimuli together with the reduction of high-amplitude long-latent auditory evoked potentials. However, significant background effect of these signals on functional condition of human subjects was observed; changes in functional condition presumably affect the activity of central parts of the auditory and associative systems of the brain which is registered as changes in the long-latent auditory evoked potentials.