title: Mean Length of Utterance before words and grammar: longitudinal trends and developmental implications of infant vocalizations.
mesh_terms: D002663:Child Language; D032882:Comprehension; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D015203:Reproducibility of Results; D012660:Semantics; D013060:Speech; D013068:Speech Production Measurement; D013997:Time Factors