A design of laryngeal structures for a physiological articulatory model

Abstract

A model of the hyoid–larynx complex is designed and incorporated into a physiological articulatory model. The previously reported articulatory model [Dang and Honda, Proc. ICSLP98] consists of the tongue, mandible, hyoid bone, and vocal tract wall. The aim of this work is to include the laryngeal structures to simulate the tongue–larynx interaction which is observed in natural speech. The framework of laryngeal structures is composed of the thyroid, cricoid, and arytenoid cartilages, which are connected by muscles, ligaments, and joints. The form and geometry of the cartilages are extracted from volumetric MR images of a male speaker and represented in a quasi-3D shape. They are modeled to yield joint rotation and translation as well as vertical movements. The ligaments and muscles are represented by mass points with viscoelastic springs, and the cartilages are composed by springs with an extremely large stiffness. Laryngeal factors of F0 control such as cricothyroid rotation and laryngeal vertical movement are demonstrated in the simulation, and plausible dynamic behaviors of the tongue–larynx interaction are observed. The performance of the model is tested by comparison of acoustic output from the model with recorded speech.