Acoustics of Infant Pain Cries: Fundamental Frequency as a Measure of Arousal

Purpose: The goal of the current study is to examine fundamental frequency (F0) from a sample of healthy newborn infant pain cries. Methods: A total of 58 healthy infants were included in the study. Data were examined from the first cry following a pain stimulus, in addition to a comparison of the first 30 seconds and the last 30 seconds of the entire crying episode. Results: In the current study, the mean F0 was found to decrease over time (regardless of infant sex, term status, or positioning). The data also showed a significantly higher F0 for preterm female infants (compared to preterm males) in the first cry immediately following the pain stimulus. Conclusions: These results reflect high levels of laryngeal tension following the pain stimulus, followed by an overall decrease in tension /arousal over time. The results support examination of the first cry following a pain stimulus, along with examination of the entire cry episode. Implications for the study of arousal and sudden infant death syndrome are discussed.