Towards a biomimetic mechatronic testbed for voice and speech

International audienceTo reproduce phonation in vitro, vocal-fold testbeds have been refined over the last thirty years, gaining in complexity and biomimicry. However, most testbeds explore the physics of phonation on geometrically-fixed replicas capable of self-sustained oscillations in fluid-structure interaction. These testbeds are not necessarily coupled to vocal-tract cavities. Where they are, testbeds rarely allow for movement of the articulators of speech, such as the jaw, tongue, velum and larynx. They usually rely on 3D-printed vocal tracts to reproduce a resonant cavity linked to a fixed vocal configuration scanned by CT or MRI. This project aims to design a complete testbed that would integrate all phonatory and articulatory aspects important for voice and speech production. Such a mechatronic testbed is under development. It consists of a silicone laryngeal envelope, a 1:1 scale vocal-fold replica coupled with a geometrically-realistic vocal tract. The vocal fold replica can be adducted/abducted, stretched into the antero-posterior direction and compressed into the lateral direction. They can self-oscillate over a wide range of flow rates and for different degrees of tensile stretch. Glottal vibratory behaviour was assessed for single-and bilayered vocal-fold replicas, for different layer stiffnesses, for homogeneous and fibre-reinforced layers. The vocal tract can reproduce several primary articulatory gestures : mandibular motion and shaping of the oral cavity with the movement of the tongue body. The applications of such testbed will be discussed