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Variability of Hearing Protector Attenuation Measurement Data: A View of Interlaboratory Studies.

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Interim rept. Jan 97-Jan 98

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The goal of national and international measurement standards is to provide consensus procedures that produce reliable qualitative and quantitative data. A standard measurement procedure is expected to produce similar results when implemented by different users. The effectiveness of hearing protection devices in noisy environments is determined using procedures that comply with hearing protector attenuation measurement standards. However, the values collected under these specified conditions do not show the expected levels of repeatability. Results in one laboratory are usually not repeat in others. The inability to achieve the expected similarity of results is attributed to the numerous sources of variability in the measurement processes and facilities. Some sources of variability cannot be eliminated others may be minimized with knowledge about the sources and proper actions initiated to counteract them. Variability is so extensive in these data that utilization of the results can increase the probability of incorrect conclusions. Variability among interlaboratory comparison studies with each using the same measurement standard are reviewed and discussed. This discussion is intended primarily, but not exclusively, for those who may not be fully informed about the measurement of hearing protector attenuation.

Subject Categories:

  • Anatomy and Physiology
  • Non-electrical Energy Conversion
  • Protective Equipment

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