For the first several months, crying is an infant's most common form of vocalization. Some cries may sound different from others, and caregivers can learn to "read" cries to some extent. For example, a "pain cry" tends to start with a sudden loud wail. This is followed by a long pause, a large inhalation, and then another wail.
- Brazelton, T. (1962). Crying in infancy. Pediatrics, 29, 579