[Vocal forcing and posture: experimental studies on normal subject]. / Forçage vocal et posture : études expérimentales chez le sujet sain.

ABSTRACT

UNLABELLED One of the well-known characteristics of vocal forcing is postural with an increase in the antero-posterior movements of the trunk and head during phonation. OBJECTIVE: we conceived different physiological experiments on normal subjects to explore in an objective way these movements. MATERIALS AND RESULTS: A series of experiments using a platform of posturography confirmed that there is an increase in the tensions in the muscles implied in the posture when the subject forces his voice because of an ambient noise. This increase is characterized by the index VCOP rms (variance of the displacement of the center of pressure in upright position) which passes from 13.19 in normal voice to 18.63 in forced voice. A complementary study was carried out with an equipment of analysis of the movements (ELITE). CONCLUSION: We could, thus, confirm the existence of the contemporary antero-posterior movements of vocal forcing. The discussion concerns the application perspectives of these experimental knowledge in the clinical field of the dysfunctional dysphonia.