Acquisition et contrôle articulatoire de la parole, croissance de l'extrémité céphalique du nouveau-né jusqu'à l'âge adulte – SkullSpeech

SkullSpeech project is designed to study the acquisition and the development of speech and its motor control in the light of its relationship with craniofacial growth from prenatal period to adulthood. To characterize the evolution of this bony architecture the project will point on the analysis of the interactions between bony elements (fixed parts) and mobile parts (mandible, tongue and hyoid bone). Craniofacial growth will be characterized in particular in relation to dental occlusion specifically studied in dento-facial orthopedics. The morphogenesis of the vocal tract depends strictly on bony structures and their development. We address the issue of how the evolution of bony architecture influences or determines the control of the mandibular, lingual and labial movements during speech production. SkullSpeech is organized in four parts: 1. The description and the modeling of the growth during ontogenesis of the skull and cervical spine and the soft tissues that delimit the vocal tract; 2. The evaluation of the mechanical tongue-teeth-palate interactions and study of the impact of the physiological functions (feeding, mastication, breathing and speech production) on the morphogenesis of the vocal tract and the bony structures. 3. The analysis and the acoustic synthesis, using a 2D geometrical and a 3D mechanical model of the vocal tract, of babbling and syllabic structures (stop consonants-vowels) which constitute the first utterances of a child from 7 months to 2 years. 4. The study of the dental occlusions; the diagnosis of the basicranial origin of malocclusions and consequently their impact on speech production. As a consequence, we will be able to better understand the speech dysfunctions, and/or orthodontic diseases which affect more and more children nowadays. SkullSpeech will focus on the relation between skull gowth and the control and mechanisms that coordinate tongue and mandible. These mechanisms are implemented during a specific period of growth, the first two years of life; they are crucial to better understand speech acquisition and also speech emergence for human species. SkullSpeech will put special effort on data acquisition and modeling. To facilitate the dissemination of the results among researchers (speech scientists, (paleo)anthropologists, anatomists), physicians and orthodontists, we shall make throughout SkullSpeech an important effort for elaborating dynamic illustrations (computer graphics) of the processes of growth of the skull and of the soft tissues and the evolutions of the vocal tract. We will add selected video tapes of speech acquistion stages. SkullSpeech is an original multidisciplinary project associating the domains of anatomy, physical anthropology, biomechanical modeling of the control of articulators, of speech acquisition and production of speech and dento-facial orthopedy.