title: Noise attenuation and proper insertion of earplugs into ear canals.
abstract: OBJECTIVE
  The study was done to determine whether the noise attenuation attained with the use of earplugs can be improved by teaching the proper insertion of earplugs to users.
  
  
  METHODS
  Fifty-four randomly selected male subjects were divided into an untrained group (25 persons) and a trained group (29 persons). The trained group was given a lecture on earplug insertion and allowed to practise the insertion procedure, whereas the untrained group acted as controls. The untrained group received this training afterwards. The success of the training was measured by the MIRE (microphone in real ear) and REAT (real ear at threshold) methods, visual evaluation and an analysis of the properties of the subjects' ear canals.
  
  
  RESULTS
  According to the MIRE method, the averaged A-weighted noise attenuation was 21 dB for the untrained group and 31 dB for the trained group. With the REAT method the attenuation at 1000 Hz was 24 dB for the untrained group and 30 dB for the trained group. The visual evaluation of the earplug fit was 1.9 for the untrained group and 2.6 for the trained group (scales 0-3).
  
  
  CONCLUSIONS
  The results indicate that training in earplug insertion is important for good attenuation and for diminishing poor attenuation to a minimum.
authors.affiliation: Pori Brigade, Garrison Hospital, PO Box 38, FIN-27801 Säkylä, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Toivonen
authors.forename: Rauno
authors.initials: R
authors.lastname: Pääkkönen
authors.forename: Seppo
authors.initials: S
authors.lastname: Savolainen
authors.forename: Kyösti
authors.initials: K
authors.lastname: Lehtomäki
mesh_terms: D000328:Adult; D004430:Ear Protective Devices; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged