Vocal fold and ventricular fold vibration in period-doubling phonation: Physiological description and aerodynamic modeling

TLDR

Period‑doubling phonation occurs in human speech, notably in pathological and certain singing styles such as Sardinian A Tenore Bassu, and involves simultaneous vibration of the vocal and ventricular folds during low‑pitch bass sounds. The study aims to characterize the physiological correlates of this acoustical production and to better understand the physical interaction between ventricular fold vibration and vocal fold self‑sustained oscillation. The authors analyzed a professional singer’s vocal and ventricular fold vibration using acoustic, electroglottographic, and high‑speed cinematographic recordings, then simulated the laryngeal aerodynamic behavior with a validated simplified physical model and compared the simulated glottal aperture to in‑vivo measurements. They found that ventricular fold closure periodically modulates glottal cycle duration and closing time, and that the estimated ventricular aperture from in‑vivo data can predict the glottal aperture.

Abstract

Occurrences of period-doubling are found in human phonation, in particular for pathological and some singing phonations such as Sardinian A Tenore Bassu vocal performance. The combined vibration of the vocal folds and the ventricular folds has been observed during the production of such low pitch bass-type sound. The present study aims to characterize the physiological correlates of this acoustical production and to provide a better understanding of the physical interaction between ventricular fold vibration and vocal fold self-sustained oscillation. The vibratory properties of the vocal folds and the ventricular folds during phonation produced by a professional singer are analyzed by means of acoustical and electroglottographic signals and by synchronized glottal images obtained by high-speed cinematography. The periodic variation in glottal cycle duration and the effect of ventricular fold closing on glottal closing time are demonstrated. Using the detected glottal and ventricular areas, the aerodynamic behavior of the laryngeal system is simulated using a simplified physical modeling previously validated in vitro using a larynx replica. An estimate of 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.