Articulatory basis of the apical/laminal distinction : tongue tip/body coordination in the Wubuy 4-way coronal stop contrast

We used electromagnetometry (EMA) to track tongue motion during productions of a rare 4-way coronal stop place series by three native speakers of the Australian language Wubuy, to assess differences in coordination of tongue tip (TT) and tongue body for Wubuy's apical (alveolar [t], retroflex [t]) versus laminal (dental [t], post-alveolar [c]) stops. Using two novel measures of TT/TB range and correlation of motion, we found support for our three initial hypotheses: 1) TB is relatively stable during TT gestures for apicals while TT-TB are coupled for production of laminals; 2) The anterior vs. posterior place contrast within each coronal class interacts with the apical-laminal TT/TB difference, which is larger for the posterior than the anterior stops; 3) The TT/TB difference between apicals and laminals is reduced in /i/ contexts (relative to /a/ and /u/) due to the high front TB position needed for /i/. Further work on other manners of coronals and other languages will help identify whether these are universal coronal characteristics (see Derrick, et al., 2014).