Infrasound — Brief Review of Toxicological Literature
National Toxicology Program November 2001
The primary effect of infrasound in humans appears to be annoyance. To achieve a given amount of annoyance, low frequencies were found to require greater sound pressure than with higher frequencies; small changes in sound pressure could then possibly cause significantly large changes in annoyance in the infrasonic region. Beginning at 127 to 133 dB, pressure sensation is experienced in the middle ear. Regarding potential hearing damage, Johnson concluded that short period of continuous exposures to infrasound below 150 dB are safeand that continuous exposures up to 24 hours are safe if the levels are below 118 dB.
There is no agreement about the biological activity of infrasound. Reported effects include those on the inner ear, vertigo, imbalance, etc.; intolerable sensations, incapacitation, disorientation, nausea, vomiting, and bowel spasm; and resonances in inner organs, such as the heart.