The recent mysteries of American diplomats falling ill in Cuba and China have fueled the hysteria surrounding international relations. Among the possible explanations are ultrasonic weapons, equipment failure, or even something mystical. Most of them reported hearing strange sounds before neurological symptoms developed. But can sound really cause harm?The mystery behind the cases of American diplomatic staff falling ill remains unsolved. First, it was Americans working at the embassy in Cuba, then similar cases were reported in China. The symptoms were the same: they heard strange noises over a course of time, and then headaches, nausea, and various neurological symptoms appeared. The media were quick to blame the country’s traditional enemies, but it seems like the cause behind the mysterious disease could be way more prosaic. While the symptoms could be attributed to brain damage–if there is something wrong with the brain, you can start hearing odd noises–it is not impossible that it was the neurological disease that preceded and led to hearing the noise, not vice versa. However, the sounds could also be responsible for the health problems reported.
Sound mattersIt is obvious that high-volume sounds can affect our hearing and do other damage, such as inducing stress, causing headaches, interfering with normal sleep, etc. Yet loud sounds are not the only source of damage. Humans’ ears are able to discern sounds within the range of 20 to 20,000 Hz. It means that everything out of the range cannot be heard. Everything below 20 is called infrasound, and everything above 20,000 is termed ultrasound. Ultrasound is used by many animals, in medicine, to deter insects and rodents, and in other industries. Infrasound is often used by elephants and other animals too. The fact that we don’t hear such noises does not render them harmless. The frequency and air vibrations are still there, and they can affect our tissues, including the brain.
Could ultrasound be to blame?It is unlikely that ultrasound could be behind the mysterious illness that stroke the diplomats, as it is generally safe: ultrasound is used to scan body organs and babies inside mothers’ wombs, so if there was some scientific evidence that would deter the scientists from using it on a daily basis with no contraindications, it would have long been withdrawn. Admittedly ultrasound can affect tissues and heat them up, but it requires contact of the source of ultrasound with the skin. Using it as a range weapon would not be effective, and it is unlikely that some device using ultrasound could have such a detrimental effect.
What about infrasound?In nature, infrasound is common: it is used by a wide range of animals as a means of communication (including giraffes, hippos, whales, etc.), and it can be caused by oceans, earthquakes, and other natural phenomena. By the way, if you want to put your ears to the test, visit this page to hear (or fail to hear) infrasound noises similar to those of elephants. Unlike ultrasound, infrasound can be far more dangerous, as it is capable of penetrating deeper and affecting the liquids inside us and any pockets, such as those in the lungs. Among the symptoms that may appear as a result of exposure to infrasound are nausea, heart palpitations, fatigue, tinnitus, etc. Sounds familiar, doesn’t it?
Whatever the cause of the cases of American diplomats, such abnormal sounds can originate in poorly designed devices or natural phenomena. If you experience similar symptoms and no underlying cause has been diagnosed, consider measuring the noises in your house: who knows, maybe there is something wrong with the environment?
Overview of Therapeutic Ultrasound Applications and Safety Considerations – ncbi.nlm.nih.gov
The Bruce McPherson Infrasound and Low Frequency Noise Study –acousticecology.org