Acoustic estimates of respiration in the pain cries of newborns.

Objective: The purpose of the present study was to examine the temporal features of pain-elicited crying demonstrated by healthy full term infants to estimate (1) the respiratory rate during cry and (2) the inspiratory and expiratory phase composition of the cry respiratory cycle.
Patients and Methods: The pain-elicited cries of 12 newborn infants were recorded within the first 2 weeks following birth. A complete crying episode was analyzed for each infant and acoustically measured for the number and duration of inspiratory and expiratory cry components. These components were then used to estimate the respiratory rate of infant crying, as well as the inspiratory and expiratory phase composition of the cry respiratory cycles.
Results: Acoustic analysis revealed that the average rate of crying was 57 breaths min⁻¹ with the inspiratory phase contributing 27% to the overall respiratory cycle. However, considerable variability was found across infants with distinct patterns of respiration associated with high versus low respiratory rates.
Conclusions: The respiratory patterns associated with pain cries is highly variable and may be associated with variations in stress-arousal, strength of emotional expression, and overall fitness. This study supports the notion that the respiratory activity surrounding newborn infant crying is unique to the type of cry sampled.
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