A B S T R A C T
Objective: The aim of this study was to investigate the acoustic characteristics of target vowels phonated
in normal voice persons while performing laryngeal telescopy. The acoustic characteristics are compared
to show the extent of possible difference to speculate their impact on phonation function.
Methods: Thirty-four male subjects aged 20–39 years with normal voice were included in this study. The
target vowels were /i/ and /e/. Recording of voice samples was done under natural phonation and during
laryngeal telescopy. The acoustic analysis included the parameters of fundamental frequency, jitter,
shimmer and noise-to-harmonic ratio.
Results: The sound of a target vowel /e/ was perceived identical in more than 90% of the subjects by the
examiner and speech language pathologist during the telescopy. Both /i/ and /e/ sounds showed
significant difference when compared with the results under natural phonation. There was no significant
difference between /i/ and /e/ during the telescopy.
Conclusion: The present study showed that change in target vowels during laryngeal telescopy makes no
significant difference in the acoustic characteristics. The results may lead to the speculation that the
phonation mechanism was not affected significantly by different vowels during the telescopy. This study
may suggest that in the principle of comfortable phonation, introduction of the target vowels /i/ and /e/ is
practical.