Simplified subset of infant vocal maturity classes (by consultation with Anne Warlaumont, UC Merced). L Y N C U Binary flag for presence of recognizable lexical content: Does the utterance contain at least one recognizable word? W 0 Binary flag for presence of multi-word utterances: Does the utterance contain two or more recognizable words? M 1 Classifications for the addressee of non-target-child speech: Is the speech directed to a child, an adult, or both? C A B P O U