Palate shape influence depends on the segment: Articulatory and acoustic variability in American English /ɹ/ and /s/

This ultrasound and acoustics study of American English /ɹ/ and /s/ investigates whether variability in production as measured in the midsagittal plane is related to individual differences in the shape of the hard palate in the coronal plane. Both token-to-token variability and variability between different phonetic contexts were investigated. While no direct relationship was found between palate flatness and articulatory variability, a secondary analysis revealed that speakers' articulatory variability for one segment was related to their variability in the other. Speakers with flatter palates tended towards lower articulatory variability scores, but speakers with more domed palates showed both high and low variability scores.