Articulatory overlap as a function of stiffness in German, English and Spanish word-initial stop-lateral clusters

Recently, Roon, Hoole, Zeroual, Du, and Gafos (2021) have offered evidence that an empirical estimate of stiffness, a parameter in the dynamics hypothesized to control the kinematics of gestures, modulates overlap in consonant clusters of Moroccan Arabic. Here, we extend the Roon et al. (2021) study in two ways. First, empirically, we broaden the assessment of the role of stiffness in overlap by examining data from three languages, largely confirming the Roon et al. results with electromagnetic articulography recordings from stop-lateral clusters spoken by German, English, and Spanish participants. Second, we examine for the first time the extent to which C1 and C2 stiffness individually, as opposed to the combined measure of stiffness difference in earlier work, contributes to overlap with the main finding being that the significant effect of stiffness difference is mainly due to C2 stiffness; C1 stiffness is not as robust as C2 stiffness in modulating overlap. These results are placed in the context of other work on articulatory and perceptual influences on inter-consonantal timing as well as in the broader context of work on the coupling between perception and action in other domains of skilled action.