An ultrasound investigation into articulatory variation into American /s/ and /r/

This ultrasound study investigates articulatory variability in American English /r/ and /s/ production in onset and coda position, and in the context of the vowels /a, i, o/. Variability both between and within participants is examined. Between speakers, our data support the position of Brunner et al. that flatter palates are correlated with less articulatory variability. Within speaker, our data suggests that articulation of either /r/ or /s/ does not predict articulation of the other.