title: Cepstral Analysis of Voice in Patients With Thyroidectomy.
abstract: OBJECTIVE
  The vocal changes after a thyroidectomy are temporary and nonsevere, therefore, obtaining accurate analytical results on the pathological vocal characteristics following such a procedure is difficult. For a more objective acoustic analysis, this study used the cepstral analysis method to examine changes in the patients' voices during the perioperative period regarding sustained vowel phonation.
  
  
  METHODS
  The sustained phonation of the five vowels (i.e., /a/, /e/, /i/, /o/, and /u/) by 35 patients with thyroidectomy were recorded by using a Multi-Speech program. Of the 35 patients, 10 were men and 25 were women, with an average age of 51.5 years. Voice data were collected a total of 3 times (preoperatively, 5-7 days after the operation, and 6 weeks after the operation) and were edited according to each fragment (on-set, mid, and off-set) for cepstral analysis.
  
  
  RESULTS
  The cepstral analysis on the patients' voices revealed no significant differences between the examination periods of all vowel phonations. However, analysis of the on-set fragment of the vowel /i/ revealed pathological characteristics in which the cepstral measurements of the voice were significantly lower after the operation than before the operation, with the cepstral measurements of the voice increasing further 6 weeks following surgery.
  
  
  CONCLUSIONS
  The results of the acoustic analysis on the on-set fragment of the vowel /i/ will be important data for characterizing the vocal changes during the perioperative period. This study contributes to future research on the mechanisms underlying changes in the voice of patients with a history of thyroid or neck surgery.
authors.affiliation: Department of Speech-Language Therapy, Howon University, Gunsan, Korea.
authors.forename: Yu Jeong
authors.initials: YJ
authors.lastname: Shin
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Research Institute of Clinical Medicine-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Korea.
authors.forename: Ki Hwan
authors.initials: KH
authors.lastname: Hong
keywords: Cepstral Analysis; Thyroidectomy; Voice