Laryngeal Constriction Phenomena in Infant Vocalizations.

Purpose Instances of laryngeal constriction have been noted as a feature of infant vocal development. The purpose of this study was to directly evaluate the developmental occurrence of laryngeal constriction phenomena in infant crying, cooing, and babbling vocalizations. Method The cry and noncry vocalizations of 20 healthy term-born infants between the ages of 1 and 7 months were examined for instances of laryngeal constriction.