After carefully recalling the True Qi running route demonstrated by the Great Monk, the two special angles of the collision of the four True Qi finally touched a dusty corner in the depths of Wang Yuetian's memory.

In a flash of inspiration, Wang Yuetian followed this familiarity, and his memory went back to his college days. This kind of True Qi collision method and collision angle is so similar to a simple sonic positioning device he invented in college to help a Bai Fumei cheat!

No wonder he was so familiar with the trajectory of this true qi, it turned out that this method of transmitting sound into the secret had a striking overlap with the current diagram he had designed.

What the great monk taught was to transmit sound into the secret, and what he made himself was also a sound wave positioning device. It seems that there is really some connection between the two.

As we all know, people make sounds through vocal cord vibration, while human voices have a weak directional transmission ability due to their low frequency and obvious diffraction phenomenon.

In other words, when a person speaks, the reason why everyone around him can hear it is because when the person speaks, the sound waves are emitted in a circle through the vibration of the vocal cords. Anyone who is touched by this sound wave will hear the sound because of the vibration of the eardrum caused by the sound wave.

The frequency range of sound wave recognition for the human ear is between 20 and 20,000 Hz, and the human ear cannot recognize sound waves below or above this range. At the same time, sound waves higher than 20,000 hertz are called ultrasonic, and one of the characteristics of such waves with higher frequencies is that the diffraction phenomenon is weak and has the nature of directional propagation.

When he was in college, Wang Yuetian used this characteristic of ultrasonic waves to modify an ultrasonic oscillation amplifier by himself, and on the rooftop 100 meters away, he helped Perecore sitting by the window to successfully cheat and pass the exam!

No wonder I feel so familiar, it turns out that I once made a device to transmit sound into the secret by myself in the previous world. Although it is used to help people cheat on exams.

Thinking of this, Wang Yuetian also felt a hint of amusement, it turned out that he had already used the legendary sound transmission technique in his own world. And for myself in the previous world, the biggest use of voice transmission is cheating.

Although the more he thought about it, the more he felt that the similarity between the two was very high, Wang Yuetian still carefully considered whether the practice route taught by the great monk was exactly the same as the sound wave locator, and whether there were some defects and deficiencies.

In retrospect, the acoustic locator I invented didn't have any advanced theories, and it wasn't too difficult to make. I simply applied some basic physics to the properties of waves, and I built the device. Compared with his own super technology experiments in the future, this device can be said to be not high-tech.

To put it simply, the principle of this device is nothing more than mixing the human voice with the first ultrasound, and shooting the mixed ultrasonic wave into the direction of Bai Fumei 100 meters away. At the same time, another ultrasound of the same frequency that was not loaded with human voices also shot at Bai Fumei.

When these two ultrasound waves are received by Bai Fumei at the same time, due to the nonlinearity of the eardrum of the human ear, the two sound waves will be remixed to produce mediation, resulting in the production of human voices that can be recognized by one ear and ultrasound that cannot be recognized by the human ear. (Just like two pebbles thrown into the surface of a lake, the ripples caused by the circle are sound waves, and when the two sets of ripples collide, they will superimpose themselves, which is the characteristic of waves.) ）

In more layman's terms, the principle of this cheating artifact is to use ultrasound as a carrier carrying normal human voices! After the first mixing, because one of the newly generated ultrasonic waves has a high frequency and good directionality, it can be transmitted to a designated place within a few hundred meters, and the people along the way can't hear anything even if they are touched by this wave because the eardrum can't recognize such a high frequency of ultrasound.

If normal humans want to hear sound, they need a second ultrasound wave to "knock out" the first ultrasonic carrier mixed with human voices, so that it can be restored to the original frequency band with a lower frequency that can be recognized by the human ear.

If you think about it this way, the reason why the exercise route given by the great monk was that the True Qi was running rapidly on Zhou Tian at the beginning, and then it was divided into four lanes, and the two collided in pairs, in order to produce two ultrasonic waves with higher frequency.

Then, while whispering, the Great Monk loaded the sound waves in the normal band into the ultrasonic waves generated by the True Qi Hedge, forming a new ultrasonic wave mixed with his own voice and hitting him. At the same time, another unloaded ultrasound wave also hit itself.

When two ultrasonic waves meet in their ears, the "supersonic plane" carrying the sound is crashed by another "supersonic plane" that follows, leaving in their ears the normal sound that can be recognized by the ears that "parachuted".

Although he figured out the principle of the double-faced Buddha sound method taught by the great monk, Wang Yuetian did not have much joy in his heart, and some were more uneasy.

The cheating artifact I made at the beginning was a revised version of the ultrasonic oscillator! Now, if you follow the practice route taught by the great monk to achieve that kind of power and produce that kind of effect, what kind of impact will this collision of true qi have on your existing body, and can your body be able to bear it?

Although his body has been repaired and transformed by nanoworms, his cell function can be said to be much stronger than that of ordinary people. However, now that I have understood the principle of this set of exercises, I have lost the meaning of exercises.

After all, Wang Yuetian was in the previous world, and his role was a scientist who experimented with others. It is not his style to let him rashly conduct a potentially dangerous experiment with himself in a non-absolute emergency.

Just when Wang Yuetian closed his eyes and thought about how he could not run this method of transmitting sound into the secret. Qingshuang City, which had been shaken by the dragon slaying artillery, suddenly fell silent.

The sudden tranquility made everyone in Frost City stunned. Wang Yuetian, who realized that something seemed to be wrong in the situation, opened his eyes for the first time, and at the same time felt that his true qi was running around his body, and he was fully alert.

At this time, the sunset had completely set, and there was no longer the dazzling dragon-slaying fire in the sky. But what is strange is that the city of Frost, which should have been plunged into darkness, is still shrouded in a dark red light. And after a little observation, you can see that this dark red blood-colored light is actually shining from the bottom of Clear Frost City!

The sight of Qingshuang City made the already noisy city explode all at once, and the people in the city immediately said anything

"Why is this land glowing?"

"Black earth and red light, this is the image of the fire dragon coming out, is this Qingshuang City a crater!"

"Bah, old man, my family has lived in this Qingshuang City for nine generations, and I have never heard of a volcano. This red light is just a temporary reflection of the red light that was previously reflected by the dragon slaying artillery. ”

"Reflective? The dragon-slaying artillery doesn't fire anymore, and there is no light, where does the reflection come from? This red light clearly comes from the ground. ”

"This... What do you know about a yellow-haired boy, but you don't understand when the old man tells you. ”

Listening to the speculation of everyone in the city, Wang Yuetian didn't know why, he only felt that the sense of danger in his heart was getting stronger and stronger! At this time, the great monk who had been frowning finally spoke, and he seemed to suddenly think of something, and said in an incredible tone

"This... Could this be a blood condensation killing array!"

Wang Yuetian couldn't help but be stunned when he heard the word blood condensation killing array. Although he didn't know what the reputation of this array was, when he even had a hint of panic in the tone of the great monk, he knew that the situation was definitely not good!

And when Zhang Yiren on the side heard the words of blood condensation and killing array, his deep pupils immediately shrank tightly, and his face, which had originally recovered a little blood, was now even paler than just now!

"Huh? Someone can still recognize this.

Hey, he's still a Jindan master?

Hahaha, Providence, this is all Providence! It seems that even God helped me Murong Ping break through the Jindan Realm in one fell swoop this time! Hahaha!!

A chilling voice suddenly sounded in all directions of Clear Frost City at the same time, making it difficult to distinguish the direction of the person.

And the people in the city who heard this gloomy sound also seemed to realize that the situation was wrong, and unconsciously looked around, as if hoping to find the source of the terrifying sound.

There were also some smart people who were closer to the city gate, and when they heard that gloomy voice calling themselves Murong Ping, and what they said about breaking through the Jindan, they knew that the situation was definitely not right. Several waves of men and horses quietly retreated towards the city gate, and it was obvious that they wanted to take advantage of the opportunity to slip away.

But when they retreated to the city gates, something strange happened!

At this time, the gate of Qingshuang City was not closed, but several people who wanted to exit Qingshuang City were walking to the city gate, and they were about to run at full speed to escape from Qingshuang City. They suddenly stopped in the city gate, and in a short time, their whole bodies were glowing with a strange red light as the underground!

With a few screams of astonishment, the originally vivid bodies dried up at a speed visible to the naked eye in just a few breaths! And the blood on their bodies spilled out of their skins and seeped into the void of the city gate!

At the originally empty city gate, a strange red wall seemed to be stimulated by blood and loomed. The strange blood-red wall was like the mouth of a long-hungry beast, and it seemed to be very satisfied with the blood of the few people who had just died, and it was smiling at the people in the city.

This strange scene made the just peaceful Clear Frost City explode again!

"What's that?"

"What's going on?"

"We're not trapped. ”

"My mother.,Monsters.。。。 ”

。。。。。

Along with the noise and crowding in the city, there were also some cultivators with a bit of cultivation who looked around, trying to find the mysterious voice just now. They understood that the owner of the voice was the one responsible for this strange event.

Seeing this, Wang Yuetian did not look around like others, but immediately looked at the great monk with the highest cultivation.

At a glance, he saw that the great monk's face at this time was rarely solemn, and a pair of eyes were staring at the mid-air of Qingshuang City.

Seeing this, Wang Yuetian immediately looked in the direction of the great monk's eyes. But at a glance, I saw that above the middle of the Sky of Clear Frost City was a void and pitch black, and there was nothing. In just an instant, a flash of inspiration flashed in his mind, and the eye of heaven opened again!

As soon as the eyes of the sky are opened, everything changes!

And the incredible scene he saw when Tianyan opened it made Wang Yuetian feel horrified!