Infrasound: a short review of effects on man.

The amount of natural and man-made infrasound that man is subjected to is larger than is generally realized. The few studies that have concerned themselves uniquely with the physiologic effects of moderate-to-high levels of infrasound exposure (as opposed to audible sound or vibrational exposures) have failed to demonstrate significant effects on man other than those concerning the inner ear and balance control. But the existing studies indicate that inner ear symptomatology due to moderate-to-high levels of infrasound may be more common than is generally appreciated. At very high sound pressure levels (greater than 140 dB), ear pain and pressure become the limiting factors. Ear muffs and ear plugs appear to offer slight protection from the effects of infrasound, but quantification of this is still lacking. Direct evidence of adverse effects of exposure to low-intensity signals (less than 90 dB) is lacking. The need for further research in this field is clearly indicated.