Almost any part of your body, based on its volume and makeup, will vibrate at specific frequencies with enough power. Human eyeballs are fluid-filled ovoids, lungs are gas-filled membranes, and the human abdomen contains a variety of liquid-, solid-, and gas-filled pockets. All of these structures have limits to how much they can stretch when subjected to force, so if you provide enough power behind a vibration, they will stretch and shrink in time with the low-frequency vibrations of the air molecules around them. Since we don't hear infrasonic frequencies very well, we are often unaware of exactly how loud the sounds are. At 130 dB, the inner ear will start undergoing direct pressure distortions unrelated to normal hearing, which can affect your ability to understand speech. At about 150 dB, people start complaining about nausea and whole body vibrations, usually in the chest and abdomen. By the time 166 dB is reached, people start noticing problems breathing, as the low-frequency pulses start impacting the lungs, reaching a critical point at about 177 dB, when infrasound from 0.5 to 8Hz can actually drive sonically induced artificial respiration at an abnormal rhythm. In addition, vibrations through a substrate such as the ground can be passed throughout your body via your skeleton, which in turn can cause your whole body to vibrate at 4–8Hz vertically and 1–2Hz side to side. The effects of this type of whole-body vibration can cause many problems, ranging from bone and joint damage with short exposure to nausea and visual damage with chronic exposure. The commonality of infrasonic vibration, especially in the realm of heavy equipment operation, has led federal and international health and safety organizations to create guidelines to limit people's exposure to this type of infrasonic stimulus.