Vocal Tract Model Adaptation Using Magnetic Resonance Imaging

We present the adaptation of the anatomy and articulation of a 3D vocal tract model to a new speaker using magnetic resonance imaging (MRI). We combined two MRI corpora of the speaker: A corpus of volumetric images of sustained phonemes and a corpus with midsagittal image sequences of dynamic utterances. The volumetric MRI corpus was used for the adaptation of vocalic and (neutral) consonantal target shapes. For each phoneme, the vocal tract parameters were adjusted manually for a close visual match of the MRI-tracings and the model-derived outlines. The resulting acoustic match of the vowels in terms of formant differences was examined and optimized. The dynamic MRI corpus was used to replicate the coarticulation of the speaker. Therefore, we analyzed the MRI tracings of the consonants articulated in the contexts of the vowels /a:/, /i:/, and /u:/. The articulatory differences of the consonants due to the different contexts were translated into a dominance model used to control the simulated vocal tract.