Inter-speaker articulatory variability during vowel-consonant-vowel sequences in twins and unrelated speakers.

The purpose of this study is to examine and compare the amount of inter-speaker variability in the articulation of monozygotic twin pairs (MZ), dizygotic twin pairs (DZ), and pairs of unrelated twins with the goal of examining in greater depth the influence of physiology on articulation. Physiological parameters are assumed to be very similar in MZ twin pairs in contrast to DZ twin pairs or unrelated speakers, and it is hypothesized that the speaker specific shape of articulatory looping trajectories of the tongue is at least partly dependent on biomechanical properties and the speaker's individual physiology. By means of electromagnetic articulography (EMA), inter-speaker variability in the looping trajectories of the tongue back during /VCV/ sequences is analyzed. Results reveal similar looping patterns within MZ twin pairs but in DZ pairs differences in the shape of the loop, the direction of the upward and downward movement, and the amount of horizontal sliding movement at the palate are found.