Mandibular position during children's defective /s/ productions.

Mandibular displacement during /s/ production was monitored via a mercury strain gauge which was taped to the face of two normally articulating and six /s/-misarticulating children. Simultaneous audio and jaw displacement visicorder traces were produced from an FM-tape recording of each experimental session, and were subsequently analyzed. Results indicated that various /s/-misarticulating subgroups exhibit different mandibular positions during /s/-production, and phonetic contextual effects upon mandibular position also vary by articulatory type.