title: Design of a clinical vocal loading test with long-time measurement of voice.
abstract: OBJECTIVE
  The aim of this study was to design a clinical vocal loading task (VLT) and to track vocal loading and recovery in voice-healthy subjects.
  
  
  METHODS
  Pilot study.
  
  
  METHODS
  Voice-healthy subjects (six female, five male) took part in a controlled VLT in the voice clinic. The VLT was designed to induce vocal fatigue. The subjects read aloud while making themselves heard through ambient speech-babble aired at 85 dB sound pressure level (SPL). Reading was terminated by the subjects when or if they felt any discomfort from the throat. The subjects wore a voice accumulator and filled out a voice activity questionnaire 1 day preceding and for 2 days following the VLT. Expert panels assessed vocal quality and laryngeal physiology from recordings.
  
  
  RESULTS
  The subjects endured the VLT for 3-30 minutes. All subjects perceived vocal loading in the VLT. All subjects raised the fundamental frequency and SPL of their speech during the VLT. No match was shown between assessment of voice quality and laryngeal physiology. The subjects showed phonation quotients of 64-82% in the task. Measurements of phonation threshold pressure (PTP) were unstable and were not used. Self-perceived vocal loading receded after 24 hours.
  
  
  CONCLUSIONS
  An authentic vocal load was simulated through the chosen method. Onset and recovery from self-perceived vocal loading was traceable through the voice activity questionnaire. The range of endurance in the VLT was an unexpected finding, indicating the complexity of vocal loading.
authors.affiliation: Department Logopedics, Phoniatrics and Audiology, Clinical Sciences, Lund, Lund University, Lund, Sweden. Electronic address: susanna.whitling@med.lu.se.
authors.forename: Susanna
authors.initials: S
authors.lastname: Whitling
authors.affiliation: Department Logopedics, Phoniatrics and Audiology, Clinical Sciences, Lund, Lund University, Lund, Sweden; ENT Department, Lund University Hospital, Lund, Sweden.
authors.forename: Roland
authors.initials: R
authors.lastname: Rydell
authors.affiliation: Department Logopedics, Phoniatrics and Audiology, Clinical Sciences, Lund, Lund University, Lund, Sweden.
authors.forename: Viveka
authors.initials: V
authors.lastname: Lyberg Åhlander
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010699:Phonation / Q000502:physiology*; D010865:Pilot Projects; D013060:Speech; D011795:Surveys and Questionnaires; D014831:Voice / Q000502:physiology*; D014832:Voice Disorders / Q000175:diagnosis / Q000503:physiopathology*; D014833:Voice Quality / Q000502:physiology*
keywords: Clinical voice assessment; Long-time measurement of voice; Vocal loading task; Vocal recovery