Pulse rate response of adolescents to auditory stimuli.

Abstract

Changes in pulse rate following auditory stimuli have been recorded in a group of 45 girls and 47 boys with an avg. age of 14 yrs. The children were chosen from the Oakland Public School population on the basis of the probability of their availability for study over a period of 7 yrs. Eight sound stimuli, consisting of a harmonic chord, siren, pistol shot, gong and 2 tones of different frequency were presented to the subject and ratings of pleasantness-unpleasantness as well as degree of startle produced were obtained. Pulse rate was recorded photographically from a pneumatic cuff attached to the ankle of the subject. Preliminary analysis showed that changes are missed if the pulse rate is counted over ten- or 15-sec. intervals, but that a 3-sec. interval is satisfactory for demonstrating rapid changes in rate. Reliability of reading the pre-stimulus levels of pulse rate was 0.96 for girls and 0.93 for boys. Sound stimuli produced a decrease in the avg. pulse rate of 3 beats per min. between 3 and 6 secs. after presentation of the stimulus with recovery by 12-15 secs. The magnitude of the displacement in pulse rate was not significantly related to degree of startle reported by the subject.