Vocal folds and ventricular bands in interaction: comparison between in-vivo measurements and theoretical predictions

International audiencePeriod-doubling occurrences have been found during singing phonations such as Mongolian Kargyraa throat singing or Sardinian A Tenore Bassu singing. The combined vibrations of vocal folds and ventricular bands have been observed during the production of such low-pitch bass-type sounds. The present study aims at better understanding the physical interaction between the ventricular-bands vibration and the vocal-folds self-sustained oscillations. In this paper, the vibratory properties of both vocal folds and ventricular bands in interaction are analysed on a professional singer by means of acoustical, electroglottographic signals and synchronized glottal images obtained by high-speed cinematography. Using the detected glottal and ventricular areas, the aerodynamic behaviour of the laryngeal system is simulated using a simplified aerodynamic modelling previously validated in-vitro on vocal-folds and ventricular-bands replica. An estimate of the subglottal pressure along with the ventricular aperture extracted from the in-vivo data allows a theoretical prediction of the glottal aperture. The in-vivo measurements of the glottal aperture are then compared to the simulated estimations. The influence of the subglottal pressure is also discussed