Studies on crying in neonates

One hundred and thirty-eight cries of 56 infants were examined during first 14 days after birth. Crying in neonates was classified into three types of situational cry: hunger cry, discomfort cry and pain cry, and the temporal patterns of each type of cry were investigated on the basis of the parameters of cry duration and cry interval. The following results were obtained: 1) In the case of the hunger cry, the cry duration was 0.69±0.31s, the cry interval 0.32±0.25s and the number of cries 9.3 ± 2.9 times/10s. The coefficient of cry duration variance showed the minimum value (=0.44) among the three types of cry, indicating that a constant cry duration was characteristic of the hunger cry. The coefficient of the cry interval variance (=0.79) was almost the same as that for the pain cry, but was lower than that for the discomfort cry. A rhythmical crying pattern was found in 72.7% of the cases of the hunger cry, which suggested a correlation between the hunger cry and a rhythmical crying pattern. 2) In the discomfort cry, the cry duration was 0.82±0.62s, the cry interval 0.41±0.32s, and the number of cries 6.7±2.6 times/10s. The maximum coefficients of variance were seen for the cry duration and the cry interval, showing that this type of crying was characterized by large variations in the parameters. A rhythmical crying pattern was seen in only 19.0% of the cases of the discomfort cry. 3) In the pain cry, the cry duration was 1.06±0.75s, the cry interval 0.39±0.92s and the number of cries 5.6±2.1 times/10s. The cry duration showed the longest value. A rhythmical crying pattern was seen in only 12.2%. 4) The cry duration of the hunger cry gradually decreased during first 8 days after birth. The cry duration of the pain cry did not change during first 5 days after birth, but decreased during 6 to 8 days after birth. The cry duration of the discomfort cry showed no sequential changes in these periods. From the results, it was evident that there were characteristics in the cry durations and intervals and also were the crying patterns of neonates in accordance with the situation of them and the number of days after birth, so it was suggested that these can serve as points to distinguish when the mother hears the infant crying.