A study of classroom acoustics and school teachers' noise exposure, voice load and speaking time during teaching, and the effects on vocal and mental fatigue development

Research output: Contribution to journalArticle

Abstract

Objectives The study investigated the noise exposure in a group of Danish school teachers. The aims were to investigate if noise posed a risk of impairment of hearing and to study the association between classroom acoustical conditions, noise exposure, vocal symptoms, and cognitive fatigue. Methods Background noise levels, vocal load and speaking time were measured on 35 teachers during actual classroom teaching. The classrooms were characterized acoustically by measurements of reverberation time. Before and after the workday, the teachers answered a questionnaire on fatigue symptoms and carried out two cognitive test tasks sensitive to mental fatigue. Results The average noise level during the lessons was 72 dB(A), but during indoor sports activities the average noise level increased 6.6 dB(A). Room reverberation time (range 0.39-0.83 s) had no significant effect on the noise level. The teachers were talking with a raised voice in 61 % of the time, and the vocal load increased 0.65 dB(A) per dB(A) increase in the average lesson noise level. An increase in voice symptoms during the workday correlated significantly with individual average noise exposure, and a decrease in performance in the two-back test correlated significantly with individual average vocal load. Conclusions Noise exposure in general classrooms posed no risk of noise-induced hearing impairment in school teachers. However, the results provide evidence for an association between noise exposure and vocal load and development of vocal symptoms and cognitive fatigue after work.

Details

Authors
  • Jesper Kristiansen
  • Soren Peter Lund
  • Roger Persson
  • Hitomi Shibuya
  • Per Moberg Nielsen
  • Matthias Scholz
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Environmental Health and Occupational Health

Keywords

  • Reverberation time, Classroom noise, Noise effects, Voice symptoms, Cognitive fatigue
Original languageEnglish
Pages (from-to)851-860
JournalInternational Archives of Occupational and Environmental Health
Volume87
Issue number8
Publication statusPublished - 2014
Publication categoryResearch
Peer-reviewedYes