title: Quantitative analysis of digital videokymography: a preliminary study on age- and gender-related difference of vocal fold vibration in normal speakers.
abstract: BACKGROUND
  Kymography is an effective method for assessing temporal patterns of vocal fold vibrations. Because kymographic data for a number of normal speakers based on high-speed digital imaging (HSDI) were limited in the literature, this prospective study was conducted to provide normative kymographic HSDI data and clarify gender- and age-related normal variations.
  
  
  METHODS
  Vocally healthy adults were divided into young (≤35 years) and elderly groups (≥65 years). Kymograms were recomposed from HSDI data at the midglottal level, and kymographic parameters were analyzed quantitatively. Then gender- and age-related differences were evaluated.
  
  
  RESULTS
  A total of 26 young subjects (9 men and 17 women, mean age: 27 years) and 20 elderly subjects (8 men and 12 women, mean age: 73 years) were investigated. Obtained data generally matched the values in the literature. Slight asymmetry was seen in all groups, with the elderly subjects having more evident asymmetry than the young subjects. Most of the kymographic parameters showed a negative correlation with fundamental frequency (F0), whereas the open quotient displayed a positive correlation with F0. There were significant intergroup differences in F0, amplitude and lateral peak at a speaking F0.
  
  
  CONCLUSIONS
  The present quantitative findings generally matched the qualitative kymographic data reported in the literature. When judging whether a vibratory pattern is normal or pathological, both gender and age should be taken into account, because gender- and age-related variations of symmetry, F0, and phase were frequently observed in the present study.
authors.affiliation: Department of Otolaryngology, The University of Tokyo Hospital, Tokyo, Japan. Electronic address: drachilles23@yahoo.co.jp.
authors.forename: Akihito
authors.initials: A
authors.lastname: Yamauchi
authors.affiliation: Department of Otolaryngology, The Tokyo Metropolitan Police Hospital, Tokyo, Japan.
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Yokonishi
authors.affiliation: Department of Otolaryngology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imagawa
authors.affiliation: Department of Communication Disorders, The Health Sciences University of Hokkaido, Ishikari-Gun, Hokkaido, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Sakakibara
authors.affiliation: Department of Otolaryngology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Nito
authors.affiliation: Department of Otolaryngology and Tracheo-esophagology, The National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Niro
authors.initials: N
authors.lastname: Tayama
authors.affiliation: Department of Otolaryngology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yamasoba
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007734:Kymography / Q000379:methods*; D008297:Male; D012727:Sex Characteristics; D013061:Speech Acoustics; D014827:Vocal Cords / Q000502:physiology*
keywords: Digital videokymography; High-speed digital imaging; Kymogram; Kymography; Normal; Voice