Although the soldiers of the expeditionary force are carefully selected elites, they have not reached the transformation level after all, and they do not have the ability to ignore the number of enemies.

If they are surrounded by the enemy and face the disadvantage of having less to many, they will have to bear tremendous pressure and even suffer heavy casualties.

In response to this situation, they summed up the countermeasure, that is, not to let themselves be left alone.

If possible, it is best to be able to gather all together, even if it is due to some situation, and it will cause some problems, they should keep the communication with each other open, and form a timely interaction according to the situation encountered.

The strange sound that the captain made like a cough and a very short one, coming from deep in his throat and listening to the strange sound that made the scalp tingle, was the medium through which the various squads of the expeditionary force communicated with each other.

As for why they chose this strange and even terrible sound, it is an accident, more precisely, a prank originating from Fengyun.

Once bored, he wanted to be scary.

If you want to be scary, you naturally have to choose a way to achieve good results.

If you want to scare people, the key is to be surprised, if the frightened object knows in advance, with psychological preparation, the effect will be much worse, or even no effect at all.

At the same time, the means of intimidation are also important, and among the various means, sound occupies a very important place.

Fengyun was about to quietly approach the target when he suddenly made a sound to startle them.

What kind of sound will have the best effect, Fengyun's mind naturally came to mind a horror movie from an island country that she had watched before crossing over, and when she first watched it, she really scared him.

In particular, the voice made by one of the characters left a psychological shadow on him, which made it difficult for him to sleep for a while.

People often have a kind of compensatory mentality, that is, they will hope that others will also taste the things they have experienced, especially some bad things.

On weekdays, they may not implement it because of various conditions, but once the conditions allow, they will do it, and even when they do, they don't realize it.

Just like some people who have been subjected to violence since childhood, when they reach adulthood, the proportion of violent measures towards the next generation is much higher than that of the general population, and a significant number of them do not feel that there is anything wrong with them.

It's no surprise that Fengyun would choose that horror movie to scare the other people with the voice that scared him.

The final effect is also very good, although the person who was scared of him has also experienced strong winds and waves, but he is still almost scared by him.

The scary effect is so good, and it is so special, it naturally left a deep impression on the soldiers of the expeditionary force, and even after Fengyun was used, it would be used by others to prank from time to time, and every time it achieved good results.

Although it is not the first time that people who are frightened have heard this kind of sound, it stands to reason that they should have a certain immunity, but every time they hear it, they will still be frightened.

The frightened people conclude that the main reason is that this sound is too eerie and terrifying, as if it has a terrifying power that can impact the soul, even if they hear it more than once, but when they hear it again, they will still involuntarily have a strong fear.

Just like the above mentioned compensation psychology, people who are scared are not willing to be frightened in vain, and always want to make up for it from other people, so that they can get psychological balance.

The same based on the psychology of compensation, what they experienced, and the same desire for others to experience the same, they also chose to be scary, and they also chose the kind of terrifying sound that seemed to have magical powers.

Regarding this kind of prank between the soldiers of the expeditionary force, a group of strong people led by the city lord of Rock City did not stop it, and even faintly revealed a sense of connivance.

They may not know much about psychology, but that doesn't stop them from understanding that people can't hold back all the time, especially when they are under great pressure.

Speaking of pressure, everyone in the expeditionary force, including the city lord of Rock City and other strong people, is under tremendous pressure at every moment.

In addition to anger and revenge, they decided to go on an expedition because of their bitter experiences.

If you are attacked by the cannibal barbarians, you must fight back, otherwise even if you win, even if the cannibal barbarians who will commit the crime in the future are killed, as long as you don't fight back, the attacks of the cannibal barbarians will become endless, and if you defeat a batch, you will soon come again.

This situation is based on a view that cannibal barbarians are even somewhat unreasonable in the eyes of the human race, and if they are attacked, they are weak and weak, and they should naturally be the target of attack.

Even if they are defeated by such "weaklings" again and again, their views will not change.

Therefore, at the beginning, the city lord of Rock City would choose to go on an expedition, but it was also a last resort.

Entering the territory of the cannibal barbarians, and getting deeper and deeper, even if the revenge is going relatively well, each of them knows very well that their situation is becoming more and more dangerous.

Although they don't choose to show it on their faces, they can't make the pressure in their hearts go away, on the contrary, it will only get bigger and bigger.

If they can't be released, they will accumulate to a certain extent, and they may even be crushed. The pranks initiated by Fengyun and popular throughout the expeditionary force may scare people, but they can effectively vent the stress in their hearts.

This point, as the city lord of Rock City who has already transformed into a powerhouse, can naturally feel it, and of course they will not stop it.

Later, when Fengyun proposed the concept of teamwork, this kind of voice, which was used by the soldiers of the expeditionary force to scare each other and left a deep impression on them, was naturally chosen as a medium of communication between each other.

In fact, there is another reason why that voice was chosen, and that is that it is very special and very easy to recognize, which is why it is especially important in the chaos of the battlefield.

At the same time, its pronunciation is also very special, it comes from deep in the larynx, and even if you can simulate it without knowing the specific pronunciation skills, you will lose the terrifying taste that makes your scalp tingle.

This can avoid being detected by the enemy, simulating their voices to interfere with them, and falling into the dilemma of being difficult to distinguish between the real and the fake.

Of course, whether they also have the psychology of compensating and want to scare the enemy, only they know.