title: Phonatory effects of airway dehydration: preliminary evidence for impaired compensation to oral breathing in individuals with a history of vocal fatigue.
abstract: OBJECTIVE
  Airway drying is detrimental to phonation and is posited to exacerbate vocal fatigue. However, limited research has demonstrated the adverse phonatory effects of dehydration in speakers reporting vocal fatigue. We compared the negative phonatory consequences of short-term oral breathing at low, moderate, and high humidity in individuals reporting a history of vocal fatigue and control participants.
  
  
  METHODS
  Females reporting a history of vocal fatigue (N = 8) and matched controls (N = 8) participated in a repeated-measures design over 3 different days.
  
  
  RESULTS
  Oral breathing at low and moderate humidity increased phonation threshold pressure (PTP) to a greater extent in individuals reporting a history of vocal fatigue as compared to controls. Conversely, PTP did not increase in either participant group after oral breathing in a humid environment. Perceived phonatory effort (PPE) ratings were poorly correlated with PTP.
  
  
  CONCLUSIONS
  The emergence of between-group differences in PTP at low and moderate but not high ambient humidity demonstrates that drying challenges might be detrimental to voice production in individuals with a history of vocal fatigue. Based on the phonatory effects of dehydration, we suggest that individuals reporting vocal fatigue may demonstrate impaired compensation to airway drying induced by short-term oral breathing.
authors.affiliation: Department of Speech, Language, and Hearing Sciences, 500 Oval Drive, Purdue University, West Lafayette, IN 47907, USA. msivasankar@purdue.edu
authors.forename: Mahalakshmi
authors.initials: M
authors.lastname: Sivasankar
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Erickson
authors.forename: Sara
authors.initials: S
authors.lastname: Schneider
authors.forename: Ashleigh
authors.initials: A
authors.lastname: Hawes
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000453:epidemiology*; D003681:Dehydration / Q000175:diagnosis* / Q000453:epidemiology*; D055154:Dysphonia / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D005221:Fatigue / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D009058:Mouth Breathing; D012720:Severity of Illness Index; D013068:Speech Production Measurement; D014827:Vocal Cords / Q000503:physiopathology*