Lowered F2 observed in uvular rhotics involves a tongue root gesture: Evidence from Upper Sorbian

Upper Sorbian, an endangered West Slavic language spoken in Germany, is unusual among Slavic languages in having a uvular rhotic /ʀ/. This paper focuses on the gestural configuration and coarticulatory resistance of the uvular rhotic and explores the relation between the articulation and acoustics of this sound. Ultrasound tongue imaging data were collected from six native speakers of Upper Sorbian, who produced /ʀ/ in word-initial, intervocalic, and word-final positions next to the vowels /e a o/. Smoothing Spline ANOVAs were used to compare tongue contours within and across phonetic contexts. Differences in the tongue root and tongue body position were also calculated across environments and compared using a measure of coarticulatory resistance. The results revealed that the sound was produced with considerable tongue root retraction and a uvular-pharyngeal tongue body constriction. The tongue root had a high resistance to coarticulatory effects, while the tongue body did not. The results suggest that the tongue root retraction into the pharyngeal cavity results in observed high F1 and low F2 effects associated with unpalatalized rhotic consonants and may explain perceptual similarity between uvular and alveolar rhotics. Articulatory constraints on the tongue root also account for phonotactic distribution of the rhotics across languages.