Does the Sound Make You Nauseous?
American diplomats in China fall ill with symptoms such as headaches, nausea and hearing loss after hearing “strange noises” in their apartments . This is very similar to what happened in Cuba in 2016, when 24 diplomats complained of strange sounds and nearly identical symptoms. Does the sound really make these people nauseous? May be.
We know for sure that sound at high volumes can damage your hearing , as well as disrupt sleep, cause headaches, cause stress and even raise blood pressure. But the sound doesn’t have to be loud to cause problems, and it doesn’t even need to be heard. It all comes down to the sound frequency, or how often the sound wave occurs every second. Humans can hear sounds in the range from 20 Hz (hertz) to 20,000 Hz. If the sound frequency is higher or lower than this range, we cannot hear it. But sound still vibrates the air and the human body, whether we hear it or not, so it can still affect us in many ways. Input ultrasonic and subsonic sound.
How ultrasound affects the human body
Ultrasonic sound or ultrasound is any sound that exceeds the human hearing threshold of 20,000 Hz. Dog whistles, plug-in pest control devices, and bat echolocation techniques are all examples of this type of sound. It is also used by doctors for medical imaging, for example, when it’s time to see a baby in the womb for the first time.
So, can an ultrasound scan cause nausea? There is some evidence that ultrasound can heat tissue through rapid vibration (or resonance ) if the emitting device is pressed against a person, but at a distance it is not very effective. Sound disappears quickly when passing through air, water and other materials, so it is unlikely to penetrate the body and cause any problems. We know this because the US military studied ultrasonic weapons and found such weapons impractical.
Basically, if you are young and have great hearing, ultrasounds may be subtle and slightly annoying, but that’s about it. After all, rodents can hear the high pitched sounds of these ultrasonic pest control devices quite well and they rarely scare them away . So, whatever strange sound made people nauseous in China and Cuba, probably not an ultrasound.
How infrasound affects the human body
Infrasound, or subsonic sound , on the other hand, is another matter entirely. These sounds have a frequency of less than 20 Hz and are more of a low hum than a deep bass note. In nature, infrasound is caused by earthquakes, lightning, ocean waves and even some animals. Elephants, whales, hippos, rhinos, giraffes and alligators are known to use infrasound to communicate with each other. You can test your hearing with elephant-like infrasound at the Cornell Lab website .
But infrasound can also be created by human hands, and it can have very strange effects on the human body. It is known to cause symptoms such as headaches, dizziness, irritation, fatigue, tinnitus, heart palpitations, and a general feeling of pressure on the abdomen. It is also not uncommon for people to experience nausea when exposed to infrasound, which is funny when you realize that the word “noise” comes from the Latin word for nausea.
All this is possible because infrasound has a long wavelength, which allows it to spread further, bend around or more easily penetrate the human body. As Seth S. Horowitz of Popular Science explains , these sounds create an oscillating pressure system that vibrates the fluid in your eyes, the gas in your lungs, and any other liquid or gas-filled pockets in your body, and this causes the tissues around the pockets to stretch and contract. One study, published in the Journal of the of The Acoustical Society of America , showed that such vibration can lead to:
“… both voluntary and involuntary muscle contractions, and can cause local muscle fatigue, especially when the vibration is at the resonant frequency. In addition, it can cause reflex contractions, which will reduce the ability to move. “
Doesn’t sound like fun, right? But you’ve probably experienced infrasound even if you didn’t realize it. Horror films and haunted houses have used a type of infrasound – or what is colloquially known as the “fear frequency” – to make viewers feel uncomfortable, nervous, and scared for years.
It is less than 20 Hz, usually around 17 Hz. Usually you can’t even tell what it’s playing unless you have a decent pair of headphones or speakers and turn up the volume.
Thus, the sound can make you “nauseous” or at least make you feel worse if you are constantly exposed to infrasound at a sufficiently high volume, such as the engine room of a large ship or a massive wind turbine. or if you spend too long in a haunted house using the frequency of fear. It’s also possible if some moron buys a “sound nausea” prank device and uses it on you, but I wouldn’t worry too much about that.