The effect of acoustic stimulus of different continuity pattern on plasma concentration of catecholamines in humans during submaximal exercise.

The purpose of the study was determination of adrenaline and noradrenaline concentrations in peripheral blood in 13 men aged 20--22 years subjected to acoustic stimulation of continuous, intermittent and pulse pattern during graded submaximal exercise. The studied subjects performed physical exercise on a cycle ergometer at workloads of 2 W/kg of body mass. The noise produced during the exercise had peak acoustic pressure of 100--120 dB, at frequencies ranging from 63 Hz to 4000 Hz. The exposure to noise and exercise lasted 15 minutes. Catecholamines in the peripheral blood were determined by spectrofluorometry by the method of Anton and Sayer. The obtained results showed that the concentrations of adrenaline and noradrenaline increased considerably in the peripheral blood during exposure to this acoustic stimulation in relation to the initial concentrations. The highest increases were observed during exposure to impulse noise.