title: Acoustic characteristics of different target vowels during the laryngeal telescopy.
abstract: 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 /ɛ/. 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 /ɛ/ was perceived identical in more than 90% of the subjects by the examiner and speech language pathologist during the telescopy. Both /i/ and /ɛ/ sounds showed significant difference when compared with the results under natural phonation. There was no significant difference between /i/ and /ɛ/ during the telescopy.
  
  
  CONCLUSIONS
  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 /ɛ/ is practical.
authors.affiliation: The Department of Otolaryngology, Hearing and Speech Center, Mackay Memorial Hospital, 92 Chung-Shan North Road, Sec. 2, Taipei City 10499, Taiwan(1).
authors.forename: Min-Tsan
authors.initials: MT
authors.lastname: Shu
authors.affiliation: The Department of Otolaryngology, Hearing and Speech Center, Mackay Memorial Hospital, 92 Chung-Shan North Road, Sec. 2, Taipei City 10499, Taiwan(1); The Department of Audiology and Speech Language Pathology, Mackay Medical College, No. 46, Sec. 3, Zhongzheng Rd., Sanzhi Dist., New Taipei City 252, Taiwan.
authors.forename: Kuo-Shen
authors.initials: KS
authors.lastname: Lee
authors.affiliation: The Department of Otolaryngology, Hearing and Speech Center, Mackay Memorial Hospital, 92 Chung-Shan North Road, Sec. 2, Taipei City 10499, Taiwan(1).
authors.forename: Chin-Wen
authors.initials: CW
authors.lastname: Chang
authors.affiliation: The Department of Otolaryngology, Hearing and Speech Center, Mackay Memorial Hospital, 92 Chung-Shan North Road, Sec. 2, Taipei City 10499, Taiwan(1).
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: Hsieh
authors.affiliation: The Department of Otolaryngology, Hearing and Speech Center, Mackay Memorial Hospital, 92 Chung-Shan North Road, Sec. 2, Taipei City 10499, Taiwan(1); The Department of Audiology and Speech Language Pathology, Mackay Medical College, No. 46, Sec. 3, Zhongzheng Rd., Sanzhi Dist., New Taipei City 252, Taiwan. Electronic address: s120185@gmail.com.
authors.forename: Cheng-Chien
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000328:Adult; D006801:Humans; D007828:Laryngoscopy; D008297:Male; D010699:Phonation; D013061:Speech Acoustics; D061351:Telescopes; D055815:Young Adult
keywords: Acoustic; Laryngeal telescopy; Phonation; Vowel