title: Effect of Training and Level of External Auditory Feedback on the Singing Voice: Volume and Quality.
abstract: BACKGROUND
  Previous research suggests that classically trained professional singers rely not only on external auditory feedback but also on proprioceptive feedback associated with internal voice sensitivities.
  
  
  OBJECTIVE
  The Lombard effect and the relationship between sound pressure level (SPL) and external auditory feedback were evaluated for professional and nonprofessional singers. Additionally, the relationship between voice quality, evaluated in terms of singing power ratio (SPR), and external auditory feedback, level of accompaniment, voice register, and singer gender was analyzed.
  
  
  METHODS
  The subjects were 10 amateur or beginner singers and 10 classically trained professional or semiprofessional singers (10 men and 10 women). Subjects sang an excerpt from the Star-Spangled Banner with three different levels of the accompaniment, 70, 80, and 90 dBA and with three different levels of external auditory feedback. SPL and SPR were analyzed.
  
  
  RESULTS
  The Lombard effect was stronger for nonprofessional singers than professional singers. Higher levels of external auditory feedback were associated with a reduction in SPL. As predicted, the mean SPR was higher for professional singers than nonprofessional singers. Better voice quality was detected in the presence of higher levels of external auditory feedback.
  
  
  CONCLUSIONS
  With an increase in training, the singer's reliance on external auditory feedback decreases.
authors.affiliation: Department of Communicative Sciences and Disorders, Michigan State University, East Lansing, Michigan. Electronic address: pb@msu.edu.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Bottalico
authors.affiliation: Department of Communicative Sciences and Disorders, Michigan State University, East Lansing, Michigan.
authors.forename: Simone
authors.initials: S
authors.lastname: Graetzer
authors.affiliation: Department of Communicative Sciences and Disorders, Michigan State University, East Lansing, Michigan.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Hunter
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000328:Adult; D005260:Female; D000068156:Formative Feedback; D006801:Humans; D007600:Judgment; D008144:Loudness Perception; D008297:Male; D009790:Occupations; D010898:Pitch Perception; D011312:Pressure; D011434:Proprioception; D063346:Singing; D013018:Sound Spectrography; D014833:Voice Quality; D014834:Voice Training; D055815:Young Adult
keywords: Auditory feedback; Lombard effect; Singing power ratio; Singing voice; Voice training