An ultrasound study of coronal places of articulation in Central Arrernte: Apicals, laminals and rhotics

This study presents ultrasound data from six female speakers of Arrernte, a language which has four coronal places of articulation: dental, alveolar, retroflex, and (alveo-)palatal. We present tongue contours for stop, nasal and lateral productions of each of these four coronal places - /t̪ t ʈ c/, /n̪ n ɳ ɲ/ and / l̪ l ɭ ʎ/ - as well as for the two contrastive rhotics of Arrernte, the alveolar trill /r/ and the retroflex glide /ɻ/. Results show that the palatal is characterized by a high and front tongue position, and the dental is characterized by a relatively low and flat tongue in the mid-to-front portion. Consistent with previous studies, the alveolar and the retroflex are difficult to discriminate, and potential differences are discussed. The rhotics are characterized by a low front portion of the tongue, and a retracted back portion of the tongue. The front portion of the tongue is lower for the alveolar trill than for the retroflex glide; and for most speakers, the back of the tongue is more retracted for the trill than for the glide. The back of the tongue is more retracted for the rhotics than for the corresponding stops and nasals, although there is evidence this part of the tongue patterns similarly for the laterals and the rhotics. It is suggested that this posterior constriction for the various liquid sounds arises from the interaction between bio-mechanical properties of the tongue and manner of articulation requirements.