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

Table of Contents

Contains the table of contents

Table of Contents

Contains the table of contents and a list of figures

Speech Communication

Contains reports on four research projects.United States Department of the Air Force (Contract AF19(604)-2061

The Voiceprint Technique: Its Structure and Reliability

Identification of individuals by the sound of their voices has long been an accepted courtroom practice. It has been accompanied directly both in the courtroom and extra-judicially, as well as indirectly with sound recordings. Voice identifications are essential to authenticating sound recordings for introduction as evidence, and are frequently the most conclusive evidence in certain types of criminal prosecutions such as those involving obscene phone calls. Until recently all voice identifications were made by the human ear, by someone familiar with the sound of the voice being identified. Although generally accepted by the courts, it has been recognized that such identifications are occasionally quite unreliable. At least one court has suggested that a highly desirable aid to judicial determinations of truth would be a scientific method of voice identification, which is not subject to human frailties

Voir la parole

Autorisation No.2107 : TIPA est la revue du Laboratoire Parole et LangageInventaire des différentes techniques de représentation graphique du signal de parole, et dressons un bilan des principales avancées scientifiques, auxquelles elles ont donné lieu dans le domaine de la recherche fondamentale phonétique et linguistique, ainsi que dans celui de la recherche appliquée aux technologies vocales (synthèse et reconnaissance automatique) et à la thérapie de la parole

The Ability of Persons with Parkinson's Disease to Manipulate Vocal Intensity and Articulatory Precision in an Intra-Operative Setting

Parkinson’s disease is a degenerative neurological disease associated with decreased basal ganglia control circuit output, leading to decreased facilitation of cortical motor areas and subsequent motor impairments (Wichmann & DeLong, 1996). Motor impairments, including rigidity, bradykinesia, reduced range of motion and difficulty initiating movement, impact both respiratory function and speech in persons with Parkinson’s disease (PWPD), often leading to hypophonia and hypokinetic dysarthria (Darling & Huber, 2011). Hypokinetic dysarthria includes, among other characteristics, reduced loudness and imprecise articulation, and therefore reduced speech clarity. The purpose of this study was to determine if PWPD were able to manipulate speech intensity and articulatory precision in soft versus loud stimulus presentation conditions in an intra-operative environment. Articulatory precision was measured using the F2 ratio, based on the second formant values of the vowels /i/ and /u/ (Sapir, 2007). As /i/ is produced anteriorly in the oral cavity and /u/ is produced posteriorly, an increase in this ratio is anticipated to accompany greater articulatory precision. It was hypothesized that PWPD would be able to increase vocal intensity, which would result in larger F2 ratios. Participants consisted of 16 PWPD undergoing surgery for deep brain stimulation and simultaneous recording in the subthalamic nucleus and cortex. Participants repeated CVCVCV utterances presented auditorily at soft and loud levels. Acoustic signals were recorded and average vowel intensities and second formant values for /i/ and /u/ productions within each utterance were extracted. Second formant values were then used to calculate the F2 ratio for each utterance. Wilcoxon Signed-Rank Tests revealed that, while intensity significantly increased in the loud compared to the soft condition, the F2 ratio did not demonstrate this increase. Of particular interest, examination of individual participants revealed that 3 patients did not increase intensity in the loud stimulus condition. When only participants who increased intensity were included in subsequent analyses, the F2 ratio did demonstrate a significant increase in the loud stimulus condition. The current study demonstrates that, even with methodological differences as a result of the intra-operative environment, when patients are able to increase speech intensity, they also increase articulatory precision