A clinical method for estimating laryngeal airway resistance during vowel production.

A noninvasive clinical method for estimating laryngeal airway resistance during vowel production is described. Resistance is calculated from the ratio of translaryngeal pressure to translaryngeal flow, the first determined from measurement of oral pressure and the second determined from measurement of airway-opening flow made during the production of a specially designed utterance. Application of the method to the study of vowels resulted in a calculated mean laryngeal airway resistance of 35.7 cm H20/LPS for 15 normal adult males. This resistance value is remarkably similar to mean values obtained in previous research using complex invasive experimental methods. Clinical use of the method is illustrated in case studies that highlight both evaluation and management potentials. It is concluded that the method proposed is clinically practical, that the data it provides are both valid and reliable, and that the method shows great promise of becoming a routine clinical tool for estimating laryngeal airway resistance during vowel production.