A comparison of vocal fold closure in rigid telescopic and flexible fiberoptic laryngostroboscopy

Fifteen normal speakers (7 women and 8 men), ranging in age from 21 to 35 years, were examined consecutively with rigid telescopy and flexible fiberscopy during sustained phonation at 3 loudness levels. The endoscopes were connected to a stroboscope and video equipment. The purpose was to investigate whether the two laryngeal examination procedures affect vocal fold closure differently. The degree of closure was judged from video tapes by 5 experienced voice clinicians who used a rating form. Intra- and interjudge reliabilities were satisfactory. The estimated degree of incomplete closure was significantly higher during rigid telescopy than during flexible fiberscopy and the difference was especially evident in soft phonation. The degree of incomplete closure decreased significantly with increased loudness, regardless of method. The importance of relating laryngoscopic findings to the loudness of phonation as well as to possible effects of the method of examination is obvious from the results.