title: Classroom Noise and Teachers' Voice Production.
abstract: OBJECTIVE
  The aim of this study was to research the associations between noise (ambient and activity noise) and objective metrics of teachers' voices in real working environments (i.e., classrooms).
  
  
  METHODS
  Thirty-two female and 8 male teachers from 14 elementary schools were randomly selected for the study. Ambient noise was measured during breaks in unoccupied classrooms and, likewise, the noise caused by pupils' activity during lessons. Voice samples were recorded before and after a working day. Voice variables measured were sound pressure level (voice SPL), fundamental frequency, jitter, shimmer, and the tilt of the sound spectrum slope (alpha ratio).
  
  
  RESULTS
  The ambient noise correlated most often with the fundamental frequency of men and voice SPL, whereas activity noise correlated with the alpha ratio and perturbation values. Teachers working in louder ambient noise spoke more loudly before work than those working in lower noise levels. Voice variables generally changed less during work among teachers working in loud activity noise than among those working in lower noise levels.
  
  
  CONCLUSIONS
  Ambient and activity noises affect teachers' voice use. Under loud ambient noise teachers seem to speak habitually loudly, and under loud activity noise teachers' ability to react to loading deteriorates.
authors.forename: Leena M
authors.initials: LM
authors.lastname: Rantala
authors.forename: Suvi
authors.initials: S
authors.lastname: Hakala
authors.forename: Sofia
authors.initials: S
authors.lastname: Holmqvist
authors.forename: Eeva
authors.initials: E
authors.lastname: Sala
mesh_terms: D000328:Adult; D005260:Female; D006685:Hoarseness / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise; D000070777:School Teachers; D012574:Schools; D013060:Speech / Q000502:physiology; D013997:Time Factors; D014831:Voice / Q000502:physiology*