Physiological Factors Controlling F: Results of a Correlation Analysis

Abstract

Many electromyographic (EMG) and aerodynamic studies have attempted to determine the physiological factors controlling the fundamental frequency of vibration of the vocal folds (F0). All of the EMG and most of the aerodynamic studies have been analyzed in a very subjective way (e.g., looking for peaks in physiological data that correspond to peaks in acoustic data). In the present study, an objective measure of correlation was obtained, for a single speaker, between EMG activity of various laryngeal muscles, subglottal pressure, and F0. The results show that the dominant factors controlling F0 depend upon the utterance type and the nature of the acoustic signal required, and suggest a model of F0 control in terms of shifts in laryngeal mode, within what is commonly considered the “chest register.” In the “low F0” mode, the larynx is quite sensitive to subglottal pressure and it is the strongest physiological correlate, while in the “high F0” mode laryngeal tension is the primary correlate. The sternohyoid muscle appears to be involved in shifting between these “modes.” Based on these promising results, further studies on more speakers are planned.