In recent years there has been a growing interest in the problem of early diagnosis of deafness in newborns, on account of the necessity of early rehabilitation. One of the methods of hearing tests among newborn is observation of changes of heart rate caused by tonal stimulation. In the present study a total of 92 newborns were examined. Each newborn received the same sound stimuli(a wable tone at 100 dB, 5 sec. in duration) from a neometer placed 4 inch from the auricle. Author noticed the general muscular response to the given tone simultaneously with registration of the heart action by ECG. The material studied was divided into three groups according to reaction observed ; minimal response group-change in heart rate from 0 to 5 beats/min. acceleratory group-change in heart rate above 5 beats/min. and acceleration pattern of heart rate response, deceleratory group-change in heart rate above 5 beats/min. and deceleration pattern. The results were as follows ; 1) Among 92 cases, acceleratory group was 46 cases(50.0%), deceleratory group was 24 cases(26.1%), and minimal response group was 22 cases(23.9%). 2) The average of poststimulus heart rate response magnitude was 10.97±6.69 beats/min. 3) The distribution of the poststimulus heart rate response magnitude was as follows ; 0-5 beats/min. was 22 cases(23.9%), 6-10 beats/min. 35 cases(38.0%), 11-15 beats/min. 16 cases(17.4%), 16-20 beats/min. 11 cases(12.0%), 21-25 beats/min. 3 cases(3.3%), and over 25 beats/min. 5 cases(5.4%). 4) The latency to peak poststimulus heart rate response was 9.95±2.88 sec. 5) The average duration of post stimulus heart rate response was 14.79±2.41 sec. 6) The distribution of intensity of muscular response was as follows ; 45 cases of strong response (48.9%), 27 cases of weak but distinct response(29.3%), 13 cases of questionable response(14.1%), and 7 cases of no response(7.6%). 7) The average of poststimulus heart rate response magnitude of questionable and no muscular response was 8.85±5.10 beats/min., but in these cases there was no case of negative heart rate response. 8) In 22 cases, comparison of percentage of postimulus heart rate response over 5 beats/min. To duration of sound stimuli -1, 3, and 5 sec-was done. 10 cases were positive(43.5%) in 1 sec duration, 12 cases(52.2%) in 3 sec. and 18 cases (78.3%) in 5 sec.