Transglottal pressure during the laryngeal vibratory cycle

Understanding of the laryngeal vibrations requires knowledge both of the properties of the vocal fold tissues and the aerodynamic forces interacting with the myoelastic ones during each vibratory cycle of the glottis. This paper reports measurements of pressure variations below and above the vocal folds during individual vibratory cycles. Pressure was recorded using miniature transducers placed in the trachea and in the pharyngeal cavity. Information on laryngeal vibratory movements was obtained by simultaneous trans‐illumination and electrical glottography. Egressive airflow was recorded using a pneumotach screen. Results indicate variations in transglottal pressure associated with changes in glottal opening. Subglottal pressure may vary 20%–40% above and below the mean pressure during each cycle, depending on phonation type and intensity level. Pressure variations showed a lag of 0.5‐1 ms in relation to glottal vibratory movements. Influences of vocal tract resonances on subglottal pressure were sometimes observed during the open part of the glottal cycle.