Aerodynamics of the human larynx during vocal fold vibration.

Objectives: : The goal of this study was to comprehensively analyze the influence of aerodynamics on laryngeal function. Three specific aspects were considered: 1) a multidimensional comparison of the interaction of subglottic pressure, sound intensity, and fundamental frequency; 2) examination of instantaneous changes in subglottic pressure during each glottic cycle; and 3) determination of the threshold subglottic pressure for vocal fold vibration and its dependence on other aerodynamic factors.

Study Design: : Prospective study with six healthy individuals without history of voice disorders.

Direct measurement of onset and offset phonation threshold pressure in normal subjects.

Phonation threshold pressures were directly measured in five normal subjects in a variety of voicing conditions. The effects of fundamental frequency, intensity, closure speed of the vocal folds, and laryngeal airway resistance on phonation threshold pressures were determined. Subglottic air pressures were measured using percutaneous puncture of the cricothyroid membrane.

Acoustic analysis of upper airway obstruction in the excised human larynx.

Upper airway obstruction is an emergency that requires quick and decisive intervention. Stridor is the sound created by airflow through a partially obstructed airway, and has been described to vary with the site and degree of obstruction. This study sought to determine the sound characteristics of stridor in the excised human larynx.

Radiofrequency treatment of tonsillar hypertrophy.

Objective: To describe radiofrequency electrosurgery and the devices and techniques available for using this technology to treat tonsillar hypertrophy.

Study Design: Review.

Methods: Electrosurgical devices, which include the Bovie, Elmed, somnoplasty, and coblation systems and argon plasma coagulators, use energy transfer by means of electromagnetic radiation to generate heat within tissue for cutting and coagulation.