Acoustic changes related to laryngeal examination with a rigid telescope

The influence on voice quality of the insertion of endoscopic equipment with tongue anchoring and head position requirements during endoscopic evaluation has not been fully investigated. The present study attempted to examine the influence of: (1) the presence of a rigid endoscope and tongue anchoring, and (2) the angle of position technique (70-degree and 90-degree) on participants' vocal output during sustained production of the vowel /i/. Five acoustic measurements including fundamental frequency (F0) values, percent jitter values, relative average perturbation of F0 shimmer, and noise-to-harmonic ratios were used to represent participants' voice quality. Results indicated that F0 values were significantly influenced by the angle of sitting position, while percent jitter values, relative average perturbation of F0, shimmer, and noise- to-harmonic ratios were affected by the presence of a rigid endoscope and tongue anchoring.