(Excerpt)

THE EFFECTS OF
VIBROACOUSTIC THERAPY
ON CLINICAL AND
NON-CLINICAL POPULATIONS
ANTHONY LEWIS WIGRAM
THESIS SUBMITTED FOR THE
DEGREE OF
DOCTOR OF PHILOSOPHY
ST. GEORGES HOSPITAL MEDICAL SCHOOL
LONDON UNIVERSITY

Many studies have been undertaken on human response to vibration at the Institute of Sound and Vibration Research in England. Griffin (1986) reports that vibration of the body can cause discomfort and annoyance, interfere with activities, present a hazard to health and cause motion sickness. He considered that the effects vary greatly according to the type of vibration, the individual and other factors. In this paper, Griffin was mainly interested in looking at the effects of mechanical vibration and he identified five responses to vibration that frequently occur:
a) Discomfort or annoyance
b) Interference with activities
c) Impaired health
d) Motion sickness
e) Bio-dynamic response

It is frequently concluded that it is hard to differentiate between airborn sound excitation of the body and vibrational excitation of the body.
There is more conjecture on the debilitating effects of low frequency vibration. Bryan and Tempist (1980) have suggested that there are some quite alarming ways in which infrasound affects human beings, such as a change in the sense of equilibrium, disorientation and nausea. They have also proposed that infrasound exposure may have been a cause of some automobile accidents.

It is known that vibration and infrasound can cause tiredness, discomfort and tracking task errors, affect vision and disturb balance organs. It should be pointed out that the sort of unpleasant subjective experiences or effects on some people of low frequency noise, including nausea, feelings of panic or euphoria are extreme symptoms and are mainly associated with high levels of intensity of low frequency noise and infrasound. Infrasound does affect the human body and physical, psychological, and pathophysiological effects which may be harmful can be measured. The sound may affect different tissues of the body in a variety of ways. Parts of the body, particularly cavities, which contain different kinds of gasses or air, such as the lungs, the intestines, the stomach, the ear and the nose are more sensitive to infrasound than parts which are homogeneous and which do not contain gasses.