title: Aerodynamic and acoustic features of vocal effort.
abstract: OBJECTIVE
  The purpose of this study was to determine the aerodynamic and acoustic features of speech produced at comfortable, maximal and minimal levels of vocal effort.
  
  
  METHODS
  Prospective, quasi-experimental research design.
  
  
  METHODS
  Eighteen healthy participants with normal voice were included in this study. After task training, participants produced repeated syllable combinations at comfortable, maximal and minimal levels of vocal effort. A pneumotachometer and vented (Rothenberg) mask were used to record aerodynamic data, with simultaneous recording of the acoustic signal for subsequent analysis. Aerodynamic measures of subglottal pressure, translaryngeal airflow, maximum flow declination rate (MFDR), and laryngeal resistance were analyzed, along with acoustic measures of cepstral peak prominence (CPP) and its standard deviation (SD).
  
  
  RESULTS
  Participants produced significantly greater subglottal pressure, translaryngeal airflow, and MFDR during maximal effort speech as compared with comfortable vocal effort. When producing speech at minimal vocal effort, participants lowered subglottal pressure, MFDR, and laryngeal resistance. Acoustic changes associated with changes in vocal effort included significantly higher CPP during maximal effort speech and significantly lower CPP SD during minimal effort speech, when each was compared with comfortable effort.
  
  
  CONCLUSIONS
  For healthy speakers without voice disorders, subglottal pressure, translaryngeal airflow, and MFDR may be important factors that contribute to an increased sense of vocal effort. Changes in the cepstral signal also occur under conditions of increased or decreased vocal effort relative to comfortable effort.
authors.affiliation: Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Rosenthal
authors.affiliation: Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York. Electronic address: slowell@syr.edu.
authors.forename: Soren Y
authors.initials: SY
authors.lastname: Lowell
authors.affiliation: Department of Communication Sciences and Disorders, Syracuse University, Syracuse, New York.
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Colton
mesh_terms: D000162:Acoustics; D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007830:Larynx / Q000502:physiology*; D008297:Male; D010699:Phonation; D011312:Pressure; D012212:Rheology; D013061:Speech Acoustics; D013068:Speech Production Measurement; D014833:Voice Quality; D055815:Young Adult
keywords: Acoustic; Aerodynamic; Airflow; Cepstral; Laryngeal resistance; Maximum flow declination rate; Pressure; Vocal effort; Voice