On the night of February 10th, 1970 the South Vietnam jungles came to life with spine-chilling sounds.
Near U.S. Army Base Chamberlain, the sounds of wailing and sobbing seemed to be coming from everywhere.
Then a voice with a warning said, “My friends, I have come back to let you know that I am dead.
It continued in Vietnamese, “Don’t end up like me. Go home, friends, before it’s too late!”
The warning followed other strange sounds such as women and children crying.
To the Viet Cong fighters hiding near the base, the sounds and voices sounded like dead soldiers.
According to Vietnamese culture, the spirits of the dead that are not returned home for burial walk the earth until they are properly buried.
Legend held that on the anniversary of their death, a spiritual channel opens for communication.
But the noises in the jungle that night weren’t the dead talking.
Instead, the sounds were a taped broadcast played by American forces.
It was all part of a U.S. campaign called Operation Wandering Soul.
And the tape playing that night was known as “Ghost Tape No. 10.”
In 1969 and 1970, American troops deployed similar recordings across South Vietnam with mixed success.
On one occasion the sounds led 150 Viet Cong fighters to abandon their positions.
One U.S. soldier said that even if the Viet Cong knew it was fake it still played on their fears of dying while away from home.
Truth is, sound has long been used as a weapon.
It can increase stress and bring about emotional reactions.
And it can distract, disorient, and even injure or kill if it reaches a certain level.
All humans respond to sound differently depending on their age, but here are typical bodily responses.
Sound between 20 Hz and 20,000 Hz are considered within the normal range of human hearing.
Sounds below 20 Hz are called infrasonic sound.
Infrasonic sound at high decibels can affect the human body.
A decibel rating above 90 dB can damage your hearing. A typical gunshot is around 140 dB depending on the caliber.
At 200 dB, you will be dead.
Sound as a deterrent:
Everyone has heard sounds that annoy them.
It could be something like a high-pitched squeal. Studies have shown that teenagers don’t like sounds around 20,000 Hz.
A hum at 20,000 Hz has been effective at moving loitering teens.
Oftentimes, people will feel the effects without actually hearing it.
An ultra-high frequency sound will disperse people.
One device that emits an ultra-high frequency is called an LRAD.
An LRAD looks like a large, black speaker and can function as a public-address system.
But it also annoys and can disperse a crowd.
If you were at a public event and began to get a severe headache or become dizzy this could be a sign an LRAD is being used against you.
The best course of action is to get away as quickly as you can before you become even more disoriented.
Sound in warfare:
Sound can cause certain materials to vibrate.
And when the sound reaches a certain level it can even cause the material to fall apart.
For example, in theory, sound weapons could be used to break down walls or shake vehicles.
In these cases, the sound waves would have to come from very large, and loud weapons.
In other words, you would know that you are being attacked.
If you were inside a building, the windows would start shattering and your body would feel the effects.
Sound that kills:
Normal decibel levels are between 0 dB and 90 dB.
These levels won’t cause any long-term damage to our bodies.
At 85 dB your body can withstand the intensity for about 8 hours.
At 100 dB your body can only withstand about 15 minutes.
At 140 dB your body will feel the physical effects.
This is why ear protection is so important.
A high-powered sound at 160 dB will destroy your eardrums and cause severe pain.
At this level, most humans would become incapacitated.
And sound can kill.
Militaries around the world have the technology to do this.
The use of sound weapons by armies and police forces around the world will continue to grow.
Even though you may not be on the battlefield, local police could use these types of weapons to disperse crowds.
The key is to look for signs and effects of sound weapons.
The most common signs are headaches, dizziness, and nausea.
If you ever think you are being targeted, you should leave the area immediately and get as far away as possible.
If you wait too long, it could be too late.
Especially as tensions in the country to continue to boil, you could face a sound weapon, even as an innocent passerby.