55 decibels is the sound of people talking normally, the sound of an alarm clock is about 80 decibels, and a chainsaw can even make 100 decibels of noise when it is working. When a jetliner is 100 meters above the ground, people can hear 130 decibels. The loud decibel sound, in f

The harm of noise is far beyond your imagination. Generally speaking, the sound is below 40 decibels and will not affect the human body; 55 decibels is the sound of people talking normally, the sound of the alarm clock is about 80 decibels, and the electric saw is working When the jet is 100 meters above the ground, people can hear a loud noise of 130 decibels. In fact, the unbearable 100dB-120dB only lasts for a few minutes. , can make a person lose hearing, which may remind you of Munch's magical "The Scream".

Judging from the current records, the Guinness World Record for the loudest sound produced by humans is still at 129 decibels. This record was set by Gil Drake of the United Kingdom in 2000, and no one has been able to break it so far. Her voice surpasses thunder, but it is far inferior to the lion's roar in martial arts movies. This is the scene of a rock concert. The sound here can reach 150 decibels, which is indeed louder than the sound produced by a passenger plane. Be big. At this time, even if you cover your ears with your fingers, it will not have any effect. When the space shuttle is launched, the sound it makes is even more terrifying. The maximum intensity is about 160dB. The sound stronger than it should be produced by the explosion of a hydrogen bomb. sound. So, how much louder is the strongest sound energy than a hydrogen bomb explosion? If the energy limit is exceeded, what will the sound become?

The answer given by scientists is that in the air, the maximum sound cannot exceed 194 decibels, while in water, the maximum sound is 270 decibels. 194 decibels, this sound was generated by a volcanic eruption. Fortunately, Krakatoa in 1883 was an uninhabited island. When the volcano erupted, there were basically no people around the island. With the Krakatau volcano erupting that year, spectacular orange-red sunsets appeared in the sky in many places around the world for several months. Krakatoa was almost razed to the ground. Some data pointed out that the following year, the average summer temperature in the northern hemisphere was shaken. The reason was that a large amount of volcanic ash was mixed into the atmosphere. They perfectly filtered out a large amount of solar radiation from the earth's surface. For several years Later, the global climate began to return to normal. The tsunami caused by the volcanic eruption was the same as the 2004 Indonesian tsunami. This deadly crisis destroyed almost everything around it.

At that time, people also discovered a 600-ton coral reef that was thrown onto the land by the tsunami. In the deadliest volcanic event on record, at least more than 36,000 people were killed. The most terrifying thing was not its destructive power, but the sound it made. Through this event, people felt The power of the loudest sound ever. It is said that at that time, the sound from Krakatoa was heard in 1/13 of the world. After this volcanic eruption with 10,000 times the energy of an atomic bomb, the eardrums of sailors operating in the Sunda Strait 64 kilometers away began to rupture; even if the sound traveled 160 kilometers, the volume reached 170 decibels. This level is enough to cause lasting harm to people at the scene. At the same time, he could also truly feel that the sound could really be as destructive as the lion's roar.

The question is, why is the sound limit 194 decibels? This is because all sound is the result of molecules hitting each other and forming an invisible link that extends from the source of the sound to the eardrum. To give a simple example, when you snap your fingers, the surrounding air molecules will be disturbed. They will collide with neighboring molecules. After that, these molecules will obediently pass this fluctuation to their nearest molecules. By analogy, when the sound reaches your eardrum, the eardrum will transmit the information to your brain. The molecules only move a short distance during this process, and what is transmitted from the source of the sound to your ears is a mysterious energy wave. This energy wave is very special. It contains a large number of molecules. High-pressure areas, but also relatively sparse low-pressure areas.

The scientific community agrees that the reason why sound has a limit lies in its "short board", which is the relatively sparse low-pressure area we just mentioned. Once it reaches 194 decibels, the sparse low-pressure area will appear completely The sight of a vacuum.Therefore, scientists concluded that at this point, the sound can no longer be louder. Because of this, scientists concluded that theoretically, at 1 standard atmosphere, the maximum sound pressure level limit that can be transmitted is 194 decibels. Nowadays, a large number of experiments have shown that strong noise fields can cause animals to die immediately. At 170 decibels, it only takes about 6 minutes for half of the mice in the experiment to fall unconscious.

Obviously, once the sound exceeds the energy limit, what people care about will never be as simple as eardrum perforation . Once the sound exceeds the energy limit, the sound becomes extremely restless, and it even pushes the air outward. This forms what we call the shock wave . What can shock waves do? The answer is that it can cause severe impact injuries. I still remember that during the Second World War, after the nuclear attacks on Hiroshima and Nagasaki, in addition to burns and nuclear radiation injuries, the most shocking thing was the impact injuries. This is the eardrum and auditory ossicles . They are the key magic weapons for humans to hear sounds, and shock waves can destroy them, causing human hearing to disappear directly. Therefore, you can also say that the loudest sound that humans can hear, which is 194 decibels, is the sound that causes complete hearing loss.