A new algorithm for temporal decomposition of speech-application to a numerical model of coarticulation

The authors propose an algorithm based on a constrained iterative optimization process using a gradient method. The constraints can be applied on the time as well as the spectral dimension. Without any temporal constraints the algorithm produces relatively compact functions which exhibit a secondary lobe structure. Applying B.S. Atal´s (1983) method each important secondary lobe is modeled by a different parametric target and associated compact function. After presenting the new decomposition technique, the authors focus on an experiment where they have been able automatically to infer directly from the speech signal articulatory gestures which intervene in a stimulus like /iyiy/ by means of an articulation with two degrees of freedom (lip protrusion versus lip opening). This study reports the first step toward a numerical model of articulatory inversion