Comparison of measures of variability of speech movement trajectories using synthetic records

In speech research, it is often desirable to assess quantitatively the variability of a set of speech movement trajectories. This problem is studied here using synthetic trajectories, which consist of a common pattern and terms representing amplitude and phase variability. The results show that a technique for temporal alignment of the records based on functional data analysis allows us to extract the pattern and variability terms as separate functions, with good approximation. Indices of amplitude and phase variability are defined, which provide a more accurate assessment of variability than previous approaches.