Measures of articulatory variability in VCV sequences

Functional data analysis is used to examine articulatory variability across repetitions in normal speech, under different movement constraints. A temporal normalization technique is applied to align trajectories of lips, jaw, and tongue in vowel-consonant-vowel sequences. Next, an index of amplitude variability is computed, defined as the mean standard deviation between peak velocities of the consonantal closure by the active articulator, in each VCV sequence. The results show that articulatory variability varies as a function of both the phonetic requirements of the consonant and the biomechanical characteristics of the articulatory structures involved.