Human ears can receive sound, but do you know the difference between the sounds we can accept? Here's what I collected for you. Why can't we stand no sound?. I hope I can help you.
The loudest voice that humans can stand?
The frequency of sound is calculated in Hertz (Hz), and the size of sound is expressed in decibels (DB). There are all kinds of sounds in people's daily life. The frequency varies greatly from 20 to 20000 Hz and the intensity ranges from 0 to 120 dB. If the sound is below 40 dB, it has no effect on the human body; When the sound is 40 ~ 60 dB, if the human body is in this environment for a long time, the nervous system will be affected. At this time, the noise energy will be doubled for every 3 dB increase in noise on average; When the sound reaches 65-80 decibels, the degree of cardiovascular injury is more than 20% higher than that of people living in 50 decibels. When the noise exceeds 80 dB, it will cause great damage to people's hearing. When the noise exceeds 100 dB, it belongs to the noise that people can't bear. The sound reaches more than 120 decibels, which is equivalent to a Boeing 747 flying by. Human health will be greatly damaged in a short time. When the sound reaches 125 decibels, it has begun to give people a headache. The human ear can withstand 160 decibels of sound. Once you exceed this number, your eardrum may have broken. The biggest sound recorded so far is the sound of karakato volcano in Indonesia in 1883. At that time, it was measured at 180 decibels 160 kilometers away. Excessive sound will cause damage to the internal organs of the human body. If a person hears a sound of 200 decibels within 20 kilometers, the pressure wave will damage his lungs, causing external air to enter the blood and causing fatal pulmonary embolism.
Why can't we stand no sound?
On the contrary, if the world suddenly has no sound, what will we do? If you are in a silent secret room - a room where you can't hear any external sound and your heartbeat and breath are weakened to 9 dB, how long can you stay? One day? A few hours? Do you think this is a rare opportunity to meditate alone, talk to your heart and listen to your inner voice? You're wrong. So far, the longest time people spend in a silent chamber is 45 minutes.
The quietest place in the world is the silencing laboratory in South Minneapolis, USA. The walls of the silencing laboratory are made of 1m thick glass fiber sound insulation cotton, double-layer insulation and sound insulation steel plate and 0.3m thick cement. The silencing effect is as high as 99.99%, so that there is almost no sound in the room! What's more amazing is that the silencing laboratory is not only "hustling outside" but also "inside". It blocks the incoming sound of the outside world and can also absorb the sound inside the room. Whether it's the usual 60 dB voice or 30 dB sleeping sound, it is weakened to 9 dB in this room. What is the concept of 9 dB? 1 dB is the sound just heard by human ears. We think it is quiet if it is below 20 dB. Generally speaking, it can be considered as "dead silence" if it is below 15 dB.
How do people feel in this dead environment? People usually determine their position by the sound they hear while walking, but in a silent chamber, you don't have any clues. You lose all the perceptual clues that keep you balanced and moving. It's an experience that makes people feel extremely lost. You'll feel overwhelmed and even unable to stand. Quiet to the extreme, like returning to the ancient uncivilized era, all kinds of hallucinations will blur your mind.
"Silent chamber" is also one of the training bases of NASA. Space is like an absolutely silent "silent chamber". Whether astronauts can maintain their concentration in this environment is very important. Only when astronauts have been trained in the silent space can they endure the silence in the future.