title: Vocal tract configurations in male alto register functions.
abstract: OBJECTIVE
  Professional male altos (countertenors) mostly use a register function, which is considered to be derived from falsetto. However, the sound produced differs in professional altos compared with the modal register or falsetto of untrained voices. The aim of this study was to analyze differences of the vocal tract shapes in male alto register functions.
  
  
  METHODS
  Dynamic real-time magnetic resonance imaging of eight frames per second was used to analyze the vocal tract profile in seven professional male altos who sang on the vowel /a/, an ascending and descending scale from G3 (196 Hz) to E4 (330 Hz). The scale included their register transition from modal register to stage (counter) falsetto and naïve falsetto.
  
  
  RESULTS
  Register transitions from modal register to stage falsetto were associated with increased lip opening, jaw retraction, elevation and back positioning of the tongue, pharynx narrowing, uvula elevation, drop of larynx height, and tilting of the larynx. Differences between stage and naïve falsetto were found mostly with regard to lip opening and pharynx width.
  
  
  CONCLUSIONS
  The differences between the vocal tract configurations might have an impact on the acoustic characteristics observed in professional male alto register functions.
authors.affiliation: Institute of Musicians' Medicine, Freiburg University Medical Center, Freiburg, Germany. matthias.echternach@uniklinik-freiburg.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Echternach
authors.forename: Louisa
authors.initials: L
authors.lastname: Traser
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
authors.forename: Bernhard
authors.initials: B
authors.lastname: Richter
mesh_terms: D000328:Adult; D006801:Humans; D007568:Jaw / Q000502:physiology; D007830:Larynx / Q000502:physiology*; D008297:Male; D009055:Mouth / Q000502:physiology*; D010614:Pharynx / Q000502:physiology; D010699:Phonation; D013061:Speech Acoustics; D014831:Voice; D055815:Young Adult