Do mothers maximize phonetic contrastivity: a study of VOT

Voice-onset-time (VOT) measurements were obtained from the productions of three adult females under the following conditions: (1) adult-directed conversation; (2) child-directed conversation; and (3) recitation of citation forms. VOT values were derived directly from frequency-by-time wide-band spectrograms by three independent judges. Results indicate adequate reliability to within 5 msec was obtained among the judges on all spectrograms. Significant differences were noted among and within the three conditions. These results are discussed in terms of current theories concerning parental roles in the infant's acquisition of language.