Effect will be particularly pronounced in initial position, because the jaw is raised highest at the beginning of a word. High jaw plus partial displacement of UL and LL from their neutral positions will result in a lip constriction, in addition to a tongue tip constriction at the beginning of the word. The correspondence between adult form and child form is quite variable in terms of a rule operation to take adult form to child form. Generalization is that child form is constrained to a particular template. In general, coronal stops follow non-coronal stops in such templates.
Child underlying representations are mostly identical to adult representations.
For production , a given underlying form is given and surface pronunciation candidates compete. For perception , a pronounced form is given, and underlying lexical representations compete. Faithfulness constraints will now determine the winner. At some time, a new constraint appears to become highly ranked, but it does not rule out production of well-practiced forms that violate the constraint. There appears to be a systematic status for the child's form of some frequently used words.