Abstract
Background: Clinical practice among noise-exposed workers is mainly focused on monitoring patients’ auditory acuity, mostly achieved through administering periodic audiograms, a practice adopted among EU-Member States. The dose-response relationship between noise levels and hearing impairment is well-established. Over the past 100 years, noise-protection has been, almost exclusively, equated with protection of the hearing function. This has diverted attention from the type of noise that does not necessarily cause hearing impairment (as measured through audiograms) but that can, nevertheless, impact workers’ health. One of the most insurmountable obstacles to scientific advancement in this field is the deceptive and crude acoustic metrics provided to the medical community, purportedly representing the noise dose to which workers are exposed. This deception is incurred through noise assessment methodologies that are imposed by the legislative bodies, and which were designed and conceived almost 100 years ago. Modern, scientific-grade characterizations of acoustic environments, however, could be providing a much deeper understanding of the signs and symptoms observed in noise-exposed workers.
Aim: To bring awareness to the medical community on how it is being greatly misled as to the real, physical dose of noise exposure of workers under their care.
Methods: Full-spectral (0.5 Hz–20 kHz) recordings were taken in several workplaces using the SAM Scribe system. Continuous recordings captured during several days were analyzed in the 0.5–1000 Hz region, using a 1/36 octave spectral resolution (instead of the imposed 1/3 octave), a temporal resolution of 1-second (instead of the imposed 10-minutes), and no frequency-weighting, i.e., sound pressure levels (SPLs) expressed in dBZ.
Results: One industry (8 workstations) was selected as an example to compare data obtained with imposed methodologies, with that obtained with more modern technologies. A- and G-weighted SPLs prove to be insufficient to characterize the dose of noise to which workers are exposed. New visual formats for evaluating noise exposures have been developed to better aid the clinician.
Conclusion: The outdated, but legally binding, methodologies used to measure noise deceive the medical community as to the dose of noise to which workers under their care are physically exposed. A serious adjustment is urgently required.