Infant cries: physiology and assessment.

It is generally agreed that the infant communicates physiological and psychological distress to caregivers by crying. Crying that is atypical in amount, intensity, duration, or quality could signal a physiological problem before the problem becomes obvious in other ways. Thus, cry analysis could soon become an important tool in early identification of infants at risk. To better assess neonatal cry sounds, nurses need some background in cry physiology. This article describes the evolution of cry sound production, presents the contemporary theories on the physiology of cry sound production, explains how cries are acoustically categorized and analyzed, and highlights the implications for infant caregivers.