Alves-Pereira, M. Low Frequency Noise Exposure as a Confounding Factor in Biomedical Science
Mariana Alves-Pereira, Twelfth International Congress on Sound and Vibration
Lisbon, July 2005
Introduction. Excessive exposure to acoustic phenomena, i.e., noise, is widely considered to cause hearing impairment, annoyance, and psychological disturbances…only. Clinical and biomedical experimentation incorporate currently accepted (but erroneous) assumptions into their research designs.
Over the past 25 years, research into the effects of low frequency noise (LFN, <500 Hz including infrasound) on noise-exposed workers, animals and members of the general population have been undermining these concepts.
Methods. A critical survey of what is known to date on the biological effets of LFN, as well as of current established research designed is carried out.
Results. Evidence suggests that annoyance is not solely a psychological situation, but a clinical sign of excessive noise exposure, either in utero, or in everyday activities. Since the effects of LFN are cumulative, human studies that focus on noise exposure without obtaining information on previous noise exposure histories cannot lead to valid results.
Similarly, conducting animal experimentation without controlling for the LFN present in the environment can lead to incorrect conclusions. Many of the complaints associated with vibroacoustic disease (VAD), a whole-body pathology caused by excessive exposure to LFN, are the object of independent studies that do not consider LFN exposure as an agent of disease, often mistakenly concluding that some other agent is the causative factor of the complaints.
Discussion. How valid are the results of scientific studies that do not take LFN into account? How valid are studies of physiological responses if previous LFN-exposure histories are unknown? LFN is ubiquitous in modern society, and continuing to ignore this fact is detrimental to the pursuit of scientific truth and, more importantly, to the well-being of human populations.