Lingual coarticulation in VCV sequences

Pulsed-echo ultrasound was used to study coarticulation in tongue dorsum movements during the production of VCV sequences. The stimuli were velar stop consonants /k/ and /g/ combined with posterior vowels /a/, /o/, and /u/. Vertical displacement, maximum velocity, and duration were obtained for all V1C and CV2 transitions. Right-left (effect of CV2 on V1C) and left-right (effect of V1C on CV2) coarticulation Was examined by stepwise multiple regression. Highly significant effects were obtained with /a/. Total duration of V1C was negatively related both to displacement from linguo-palatal contact to the point of maximum velocity and to total displacement of CV2 (RL effects). Total displacement and maximum velocity of CV2 were negatively related to the displacement to the point of maximum velocity and total displacement of V1C (LR effects). The LR effects of V1C on CV2 were larger than the corresponding RL effects. Similar patterns were obtained for both intervocalic consonants. The findings are discussed in terms of the contributions of mechano-inertial and motor timing effects to coarticulation.