First of all, the dense smoke on the crater greatly affected the trolls' ability to observe with the naked eye.

Secondly, the monsters inside the lava rarely burrow out of the molten lake, which seriously slows down the execution of this exploration activity.

So at this point, although the whole team has been here for a while, the results they have obtained are really limited....

~~~~

On a mountain pass in one of the active volcanoes, two trolls are teaming up on a mission.

The task of the upper peak is to have them responsible for recording the number and size of the lava monsters in this magma lake.

The two of them took turns to rest and work, and kept writing and drawing with pen and paper seriously, but in the end, there were no achievements worth showing off, and they couldn't even tell how many monsters they had memorized.

Eventually, one of the trolls began to think differently, and he closed his eyes, trying to tell the difference by hearing alone.

[In view of the general environment,

Although I don't know if he really thinks this kind of method works, or just wants to be lazy.

But it didn't matter, because the troll really figured something out.

The volcanic smoke seemed to have sharpened his sense of hearing;

Some strange sensations came intermittently from the craters in front of me, and even from other craters hundreds of meters away.

They mingled between the wind and the sound of lava tumbling, and a slight rhythmic pick up in his ears caused him a vague sense of discomfort.

But this feeling is relatively ambiguous, he is not sure whether he is "listening" or not, even if he leans over and closes his ear to the rock wall of the mountain pass to listen carefully, he still receives some unclear perception.

However, he found a little familiarity, and this sense was still unfinished.... It seems to be somewhat similar to how I felt when I received the infrasound signal?

Explorers who have received popular science and know the concept of "recognizable frequency bands" have tried to open the corresponding totems on their bodies, trying to see if there is any trace of the culprit that causes their discomfort from the infrasound signal.

After a while, under the strange gaze of his partner, he took out the paper from his bosom, as well as the new "compound no-dip pen" with the tail to store dye, and drew on the pen instinctively.

"What are you doing, is there a signal?"

It seemed that looking at the undulating lines under the brushstrokes, it felt that it was a record of the transmission signal, so the companion asked with some confusion.

"Shhhhhh Wait."

At this point, the two trolls fell into silence, and all that remained for them was the rustle of the tip of a special steel and wood pen on the paper.

After half an hour, the troll with his eyes closed stopped writing, opened his eyes, looked at the folded line he had recorded in front of him, and fell into thought.

On paper, in addition to a few relatively clear line segments, there are also many folded lines that only start at the beginning or end abruptly when the first half of the line is drawn.

And these are basically sound sources that he can't distinguish.

They are either entangled with each other or mixed with the natural context, in short, they cannot be discerned by their own ears and analytical skills.

But how to put it, he always felt that there was something in the lake, and even in the surrounding background sounds, which brought a very familiar sense of trajectory... Like a creature's heartbeat?

However, since you can't do it yourself, let's leave it to the above to try....

The news was passed on in through repeated attempts, and finally reached Zhuo Erling, who was located in the headquarters.

She looked at the analysis application in her hand and the questions recorded on it, and had no choice but to submit a request for support to the Ministry of Communications.

Not long after, the professional infrasound analysis team directly under the Ministry of Communications rode a moose to the southern exploration front;

There, they first met with the director of the Southern Exploration Division, who was temporarily stationed here, and after a brief exchange between the two sides, they approached the direction of the volcano together

And go.

Upon arrival, the support team immediately began to work, analyzing the sonic signals that the exploration team could not analyze in detail.

~~~

If a normal sound sounds like a beautiful rhythm connected in a line;

At this time, the infrasound environment faced by the team was like a snowflake screen on a TV, in which countless frequency bands of signals were mixed, and they interfered with each other to form an extremely complex background.

According to the sample data that the exploration team barely decomposed, the support team compared and searched in the "snowflake screen", trying to distinguish all the similar sound sources of the same type.

In the next few months of analysis and re-acceptance, the two teams cooperated to calibrate no less than 100 approximate bands in the crater in front of them.

At this point, people don't really know what these sounds are, and they can't even be sure if they are connected;

I just thought about finding them......

"You say, could it be a heartbeat?"

This kind of nonsensical speculation was not taken seriously at first, because if it came true, it would mean that there would be at least hundreds of monsters in this crater under your bare feet.

Haha, how can you.... Yes?

After all, neither side was old and stubborn, and with nothing to do, the support team and the exploration team tried to move two steps in this direction as if they were looking for something to do.

As a result, everyone found that the speculation was getting more and more like that.

Ahh I don't know how deep the crater lake is, and I don't know how much life is there;

Although they had thought that there might be many monsters in a volcano, the trolls had never imagined that there could be so many of them.

And, that doesn't seem to be the whole problem.....

"What the hell is going on, this mountain tip and the base of the mountains below it look like it will only be about 3,000 meters, how does it sound like a bottomless pit?"

"I feel that way too..... There are a large number of secondary sound signals that look at the attenuation amplitude, as if they are coming from 500 kilometers away, and the number of monsters inside is different every time..... It's like taking turns to come up on vacation? If those signals really represent monsters."

"Report it, it's beyond our reach, and we can only let the Witch Doctor take action himself."

"This... Okay."

At the discretion of the Ministry of Communications support team, the matter returned to the ruling government and was sent to several witch doctors in circles.

Flipping through the report that formed the chart of the paperwork, several witch doctors who got the news first seemed to think that this was something worth caring about.

Therefore, instead of going directly to the scene to help, they sent it to the council for discussion, making the issue officially in the eyes of all the witch doctors.

~~~~~

Mother Tree Venue.

Nesta was also present at the meeting, and at this time he was distracted with the report from the communications team....

One of the maps is a simulation of the area's topography, with the analysis team's assumptions about the environment beneath the volcano based on acoustic feedback.

The appearance of the world beneath the surface of this world seems to be roughly similar to that of the earth in the previous life;

At least, under the investigation of the witch doctors, it has been basically determined that below the sedimentary layer of the Black Forest Plain is a double-layer crustal structure with a thickness of about 120 kilometers.

Further down in the earth's crust is a "solid layer under the shell" whose depth even witch doctors cannot determine.

However, the report submitted by the analysis team after visiting the volcanic group changed this view to some extent;

In their observations, beneath the crater was an extremely deep layer of fully liquid geology that exceeded the depth of the earth's crust.

The witch doctors weren't surprised at this, but thought it was something to do with stress.....

But the next report

, but they were suspicious;

The team believes that the previously observed lava organisms may not be populations living in "shallow" craters or even in the underlying pedestals.

Perhaps, the "all-liquid geological layer" located further down and extending somewhere, should be their real nest?

In addition, there are quite a few "suspected life reactions" that appear suddenly in a fixed period of time and disappear again after a certain period of time, and so on.

But at the same time, there is another part of the "suspected life" that is always present in the crater and some of the "surface" areas that can be explored.

Of course, in fact, the team is still sure whether these are "life reactions" or not, but based on their own perception, they feel that this is a possibility.

Therefore, the word "suspected" is always used in the report to accurately describe...

After all, trolls have evolved into a visual species, and no amount of keen hearing, especially in such a deep and distant situation, can not give them the peace of mind that "sight" can bring.

~~~~

After reading the report, Nesta became more interested in the volcano;

Moreover, with the specific sample data of the team as a reference, with the ability he has now, he does not really have to travel thousands of miles to the volcanoes in order to make effective adjustments;

Now, he only needs to find a quiet room on the mother tree, and he can make a more detailed distinction between the infrasound response of the volcano according to the sample of the gourd drawing.

At the same time, this report gave him another inspiration....

Based on the rhythm of the infrasound, the team guessed it as a "life response", but what exactly is a life response in infrasound?

Is it volcanic monster activity? Or viscera... If they have, the movements carried out?

Then, Nesta further thought, does our body make infrasounds?

Do the other creatures in the Northlands, or the rest of the region, make infrasounds?

This "emanation" does not refer to the active application of infrasound in the same way as speaking or using magical abilities;

It's the kind .... Without knowing it, because of the movement of the viscera or other reasons, it unconsciously emits a low-frequency infrasound.

With such an idea, he temporarily put aside his intention to explore the volcanic monster and decided to study this aspect first....

If it turns out that his conjecture is true, then the exploration of the Quartet in the future may not be so laborious....

At the very least, the three advanced ones, including him and Azhara, could use the distant infrasound signals to give relatively accurate instructions to the rest of the trolls in that direction, even if they were sitting in the headquarters or going out to the northern or northeastern fortresses.

Of course, this will have to be done by asking the exploration team to capture some foreign living creatures and let them have the initial sample data.

~~~

The target, first of all, is the phenomenon of infrasound generation on the trolls....

To this end, Nesta first created a confined space surrounded by low-pressure multi-layer walls on all six sides, to minimize background noise in the experimental environment;

After that, the sound environment in the space is recorded when there is only one troll alone;

After that, open the wall, bring in a troll, and seal it to shut it out, once again insulating it from outside sources.

Compare the differences in the sound environment between the two scenes..... After repeated experiments, he finally found that unique wave frequency;

After subsequently replacing the rest of the compatriots, the special oscillating infrasound signal that is different, but still very similar, was observed again.

It is concluded that although it is not known whether it originates from the viscera or not, the existence of the troll itself does have the ability to produce infrasound, and this infrasound frequency band is roughly in the recognition range represented by -8.

In the past, troll infrasound was mixed in with natural background sounds, and it didn't

Get his attention;

But starting today, Nesta will be able to classify and identify such signals.

After that, the first thing he did was to give the sample spectrum to Azhara, Fang, and Roughfang, three advanced witch doctors who could also do this;

After they tried and succeeded, the four advanced witch doctors worked together to begin the "infrasound recognition memory" of the most important trolls in the country.

For example, they are each other, the government executives, the top military officials, the elf girls, the qualified teenagers in the central school, the technical elites in the tribe...

By memorizing their infrasound bands, at least within a range of two or three thousand kilometers, the four witch doctors can locate these special trolls;

Although this positioning will be delayed due to the speed of sound, it is much better than not having nowhere to find it at the end of the day.

As for the right to privacy .... Not to mention that the sense of private rights in the republic has not yet reached that point, even if the society progresses in the future, the protection of special trolls will continue;

If possible, there will even be a different way to achieve real-time positioning....

After that, they collected infrasound samples of the existing live animals in the headquarters;

Including moose, wind and waves at all levels, black blade-toothed beasts, mountain giant bears, etc., none of them escaped the "poisonous hands" of the four advanced witch doctors.

Of course, for these species, it is good to only remember the value of one racial zone, and there is no need or energy to do any special individual memorization.

After jotting down the many samples of information, Nesta climbed to the top of the Mother Tree, where she found a Wind Chime meditation room and drilled into it.

In the quiet room, he started from the normal frequency band, and continued to expand his voice reception ability one magnitude after another.

Ten kilometers, 100 kilometers, 500 kilometers, 1,000 kilometers, unknown distance.....

The ultra-low frequency signals from afar are all reduced to a certain level of band, because those that do not meet this standard have been dissipated into the atmosphere in this long road;

However, only the remaining part of the semaphore is already considered an extremely dense cluster.

As the distance approaches, the various infrasound signals become more and more complex, and the signals of various bands are mixed into "hairballs", which are almost impossible to distinguish.

But Nesta didn't try to distinguish anything at this time, he just quietly "listened" to these "yarn balls" and fell into fantasies.

He knew that some of these messages could come from distant volcanic eruptions, or some of them could be groans between tectonic plates;

Or perhaps, there is also the roar of meteorites hitting the ground, the turbulence of the atmosphere in the sky....

"But I'm only a limited number of them, and it's a shame.... In the future, we must see all these phenomena again."

With such a sigh of involuntary emotion in her heart, Nesta began to refuse to read the sound message one by one, sequentially stripping away the waste signals that could not be used because there were no samples from the spiritual world;

In the end, only the signal from the part of the country that had just been written down remained.

Judged by himself to be elite and extremely potential, there are about 500 or so trolls, except for a bunch of witch doctors densely stuffed on the side of the mother tree, the rest are distributed in various areas of the headquarters.

Finding it interesting, Nesta began to try to give them form in meditation, to clothe the sound signals with the skin they emitted;

Soon, Azara, Fangs... Giant Fang, Cui Wenli, Zhuo Erling.... These trolls appeared in their meditations and performed various actions under Nesta's control.

Of course, among them, Azhara is the most agile, and the rest are a little stiff, with a mechanical sense of both frowning and laughing.

Later, Nesta relied on his memories to reconstruct the environment in which they should have existed, and the mother tree, the government office building, the military barracks, and even the main street and other exterior scenes also appeared as background panels.

Time passes by a fraction of a second

, Nesta came back to his senses, and found that he had actually forcibly reproduced the overlook of the entire old and new cities in the meditation space almost completely.

"This..."

Trying to focus his "gaze" on a specific area, he gradually lowered his vision from a high altitude as he did in his previous game, and at the same time tried to "high-definition" the area.

As the resolution became higher and higher, gradually, he could see the slate lines in a certain courtyard closely, and he could clearly "see" to the top of the mother tree from afar, and see the meditation room where he was at this time;

Almost everything in the entire city of Motobe, as long as he had seen or known, appeared in Nesta's mind in a fairly clear posture at this time.

It was only then that Nesta finally realized that she was tired, and she desperately wanted to sleep.

After feeling this, he immediately disbanded the "playground" in the meditation space, and turned his head down in this room, found a good lying position and slept.