Effects of laryngeal endoscopy on the vocal performance of young adult females with normal voices

This study investigated changes in maximum phonation time and acoustic and perceptual measures of voice following topical anesthesia and laryngeal endoscopy with the flexible endoscope. Forty-four females, aged 18-33 years and with normal voices, performed four vocal tasks: (a) 3-second /i/ prolonggation, (b) maximum phonation time on/i/, (c) stepwise scale-singing, and (d) reading a standard passage. Subjects performed these tasks prior to anesthesia, after anesthesia, and again during laryngeal endoscopy. Voice samples were analyzed for jitter, shimmer, harmonic-to-noise ratio, speaking fundamental frequency, maximum phonational frequency range, maximum phonation time, harshness, and breathiness. Results demonstrated significant reductions in maximum phonational frequency range following anesthesia and, during laryngeal endoscopy, reductions in maximum phonation time and increases in speaking fundamental frequency, minimum fundamental frequency on scale- singing, and breathiness. Clinicians using laryngeal endoscopy for evaluation and management of vocal dysfunction should, therefore, consider the possible effects of these procedures on vocal functioning.