Human vocal tract growth: A longitudinal study of the development of various anatomical structures

International audienceThe growth of the head and neck and its components, including that of the vocal tract, is not homothetic but appears rather as an anamorphosis. The growth of various structures presents a phenomenon of heterochrony. Another important issue in vocal tract growth is sexual dimorphism. It was first claimed that sexual dimorphism appears at puberty, but a recent study has suggested that some prepubertal differences exist. To study these two phenomena, we used longitudinal radiographic data of sixty-eight typical subjects (966 radiographs, taken from 1 month to 25 years) and twelve fetuses (anatomical sections). In this study, we analyzed the growth curves and growth types of the hard and soft palate, the pharyngeal cavity and the estimated length of the whole vocal tract using non-linear mixed-effect models, in order to take advantage of our unique longitudinal dataset. Results indicate that most of the structures follow a neural/somatic growth type, while the pharyngeal cavity follows a more somatic growth type. As concerns sexual dimor-phism, no prepubertal differences were found, suggesting that the sexual dimorphism is likely to begin at puberty. These results have implications for the acoustics of speech production during development and should lead to improvements in vocal tract growth modeling

rlaboiss/vextab-data: version 1.1

In this release, preliminary documentation for the data format and the Python/R scripts is included

Data from: Relationship between spectral characteristics of spontaneous postural sway and motion sickness susceptibility

Motion sickness (MS) usually occurs for a narrow band of frequencies of the imposed oscillation. It happens that this frequency band is close to that which are spontaneously produced by postural sway during natural stance. This study examined the relationship between reported susceptibility to motion sickness and postural control. The hypothesis is that the level of MS can be inferred from the shape of the Power Spectral Density (PSD) profile of spontaneous sway, as measured by the displacement of the center of mass during stationary, upright stance. In Experiment 1, postural fluctuations while standing quietly were related to MS history for inertial motion. In Experiment 2, postural stability measures registered before the onset of a visual roll movement were related to MS symptoms following the visual stimulation. Study of spectral characteristics in postural control showed differences in the distribution of energy along the power spectrum of the antero-posterior sway signal. Participants with MS history provoked by exposure to inertial motion showed a stronger contribution of the high frequency components of the sway signal. When MS was visually triggered, sick participants showed more postural sway in the low frequency range. The results suggest that subject-specific PSD details may be a predictor of the MS level. Furthermore, the analysis of the sway frequency spectrum provided insight into the intersubject differences in the use of postural control subsystems. The relationship observed between MS susceptibility and spontaneous posture is discussed in terms of postural sensory weighting and in relation to the nature of the provocative stimulus

Phonetic Code Emergence In A Society Of Speech Robots: Explaining Vowel Systems And The Muaf Principle

The purpose of this paper is to explain how it is possible to simulate the emergence of a common phonetic code in a society of speech robots using evolutionary techniques. Simulations of the prediction of vowel systems and the explanation of the Maximum Use of Available distinctive Features (MUAF) principle are discussed. These experimental results show how simple local rules of interaction between robots may explain some of the universals characteristics of the phonological structure of world's languages. On going work aiming to answer more complex questions, such as the use of supplementary features in large vowel systems, is presented. 1. INTRODUCTION The origins and evolution of language is still clouded in mystery. Typological studies [7] have shown that the sound systems of world's languages exhibit systematic structural characteristics. The most common hypothesis is that language is based on human innate ability and on the refinement of innate language (universal grammar) by a..

SPECIES: an evolutionary model for the emergence of phonetic structures in an artificial society of speech agents

Colloque avec actes et comité de lecture.This paper addresses the emergence of a common phonetic code in a society of communicating speech agents using evolutionary techniques. Predictions for the large vowel systems of the world's languages using the Maximum Use of Available distinctive Features (MUAF) principle are discussed. Simulations of the use of supplementary phonetic features in large vowel systems are presented. These experimental results show how simple local rules of interaction between speaking agents are sufficient to explain some of the universal characteristics of the phonological structure of the world's languages

SPECIES: an evolutionary model for the emergence of phonetic structures in an artificial society of speech agents

Colloque avec actes et comité de lecture.This paper addresses the emergence of a common phonetic code in a society of communicating speech agents using evolutionary techniques. Predictions for the large vowel systems of the world's languages using the Maximum Use of Available distinctive Features (MUAF) principle are discussed. Simulations of the use of supplementary phonetic features in large vowel systems are presented. These experimental results show how simple local rules of interaction between speaking agents are sufficient to explain some of the universal characteristics of the phonological structure of the world's languages

Higher order modes propagation in the human vocal tract

International audienceThe representation of the vocal tract in terms of its cross sectional area function is useful to obtain an approximation of the acoustics of the vocal tract based on plane waves, which takes into account only for longitudinal resonance modes. However, for frequencies above 4 or 5 kHz (depending on the vocal tract geometry), transverse resonance modes can have a significant effect and must be taken into account. In this paper, we describe a method to calculate the vocal tract acoustics for the case of cross-sectional shapes measured by MRI. Since these shapes are arbitrary, a method to numerically derive the eigenfunctions and eigenmodes has been implemented. Validation of this method has been performed by comparison with analytical solutions for rectangular and elliptical geometry. First a comparison between the results obtained with this new method and the classical approximation using a concatenation of uniform ducts of rectangular or elliptical cross-sections is presented. The effect of higher acoustical modes is illustrated on the basis of not only the transfer function but also on the radiated sound pressure field. Then, the results obtained by numerical simulation are compared with acoustical measurements performed on mechanical replicas of the vocal tract with various shapes

Raw posturographic and MS data

This ZIP file contains the center of pressure (CoP) data and the MSSQ and SSQ scores for all subjects included in the study. For details, please see the file README.pdf contained in the ZIP file

Real and visually-induced body inclination differently affect the perception of object stability

International audienc