After deflated and folded the Zodiac on the beach, Zhang Zian drove back to the pet shop contentedly. There is no need to return the underwater pickup to Professor Wei Kang in a hurry, because it is not known whether the recorded sound is complete. Although he doesn't understand whale language, he knows that language is very complicated, and he can't learn it just by listening to a few bits and pieces.
If Shihua said that the length of the recorded voice was not enough, then he would continue to repeat what he did today until she was satisfied.
"Master, you are back, Godzilla... No, did you record the voice you wanted?" Wang Gan ran over and picked up the battery, asking inexplicable words.
"Well, it's probably recorded. I'll edit it later and make a copy. You can take it to Li Kun and let him play it as background music in the aquarium on a loop." Zhang Zian ordered, and at the same time picked up a full set of underwater equipment. Pick up equipment and go to the second floor.
Wang Gan agreed and returned to the store to charge the battery.
π has just finished writing a chapter and is stretching and walking back and forth in the living room, exercising his body.
"π, I'll use the computer, it will be fine in a while."
"Squeak."
Zhang Zian took out the memory card in the device, installed the supporting sound spectrum analysis software in the computer, and then imported the original audio files in the memory card.
The sound is converted into a waveform and output on the screen, but it is very disorganized, just like the K-line charts of a thousand stocks are displayed at the same time, it is dazzling to see.
He studied the usage of this software, called the filter to filter out all the high-frequency sounds, and the screen became much clearer immediately, but there were still hundreds of curves left.
He then dragged the timeline further to find the end of the audio file.
He roughly remembered when the sound of the giant whale appeared, and by comparing the time of appearance and end, he further eliminated more than 90% of the noise, leaving only a few curves.
Due to his lack of experience, the remaining curves could not be easily eliminated with the sound graph, so he simply selected these curves one by one in a clumsy way, and then played them.
Boom...
despair…
Ka...
Ding…
hiss…
All sorts of voices blared in turn from the laptop's puny speakers, some of which were beyond human hearing and could only be audible after being enhanced by software.
Strange to say, he was already very focused at the time, but he still felt strange when he heard these voices, as if he had never heard them before.
"Squeak."
π scratched his ears and scratched his cheeks, as if his whole body was itching, obviously it was uncomfortable to hear some too weird sounds, and finally he simply plugged his ears, jumped into the wicker chair in the hanging basket, and covered his head with a pillow.
Woo
A familiar voice sounded.
Zhang Zian's heartbeat suddenly accelerated.
Can't go wrong! That was the voice I heard! Like the sound of a train whistle, the sound periodically increases and decreases, and occasionally it is mixed with a sound similar to that of train wheels rolling over the junction of railroad tracks.
After finally finding it, he held down the left mouse button and did not dare to release it, for fear that this curve would be submerged by other curves after releasing it, so he dragged it to create a new window independently.
In the new window, this curve is shaped like a periodic uplifted mountain, one side is steep and the other side is gentler, the mountain peak has several undulating peaks, this is the sharpest part of the siren, and the highest point often corresponds to the bang .
In the coordinate axis where the curve is located, the x-axis represents time, and the y-axis represents the frequency of the sound.
He moved his eyes and looked at the y-axis.
"Um?"
He froze.
Only a few species of whales have grown to such a huge size. If you exclude the right whale with keratinoma on its head, and the toothed whale such as the sperm whale, there are not many choices left.
Zhang Zian originally thought that the giant whale was a blue whale or a fin whale, but the numbers on the y-axis indicated that he was completely wrong.
The frequency band of the blue whale's sound is basically between 15 Hz and 40 Hz, mainly concentrated within 15 to 20 Hz. In recent years, due to the excessive noise made by humans in the ocean, there is evidence that the sound frequency of the blue whale is gradually moving to the lower frequency. shifted, closer and closer to 15 Hz to avoid conflict with human noise.
The vocal band of fin whales is more narrow, between 15 and 25 Hz, mainly concentrated around 20 Hz.
The hearing range of the human ear is 200,000 to 20,000 Hz. Without the aid of instruments, humans can basically not hear the sound of blue whales and fin whales.
However, the frequency range corresponding to the y-axis on the screen is between 45 and 50 Hz, and this frequency can be directly heard by the human ear.
Strange, is there something wrong? Isn't this curve the sound curve of the giant whale
Some whales have a wide range of voices and can cover this range, but those whales can't grow to such a large size.
After Zhang Zian thought about it, the most normal and reasonable explanation was that when he was recording the giant whale, there was another whale of a different kind lurking in the nearby sea. He thought it was the sound of a giant whale, but it was actually another whale.
But is there such a coincidence
If this is the case, where did the sound curve of the giant whale go
He switched back to the original window and played the remaining curves one by one again. To his headache, he couldn't determine whether these sounds were from whales.
If only there was an experienced submarine sonarer here who would be able to tell him what these noises are all about.
He was a little depressed. He thought that all his achievements would be done in one battle, but now it seems that he will go to record a recording tomorrow. I hope he will not make a mistake next time...
Wait, is it really a mistake
He tries not to let go of every possibility.
If I'm not mistaken? What if the recorded sound tomorrow still has this abnormal sound curve
It can't be that there is always a mysterious and never-showing whale following that giant whale all the time, right
There is an ultimate elimination method called "Occam's Razor Law", which can be expressed in the simplest terms as "don't multiply entities unless necessary".
From the avenue to simplicity, the simpler the better.
Specifically, when two hypotheses have exactly the same explanatory and predictive power, we use the simpler hypothesis as the basis for discussion.
Zhang Zian became alert and realized that he was making a mistake. In order to explain the abnormal phenomenon, he added another whale that physically followed the giant whale, which was mysterious and never showed up.
Is this entity really necessary to increase
In fact, there is obviously another explanation that can achieve the same effect. The sound of the giant whale is like this, and there is no other mysterious whale.
Which of the two explanations is simpler? Obviously the latter.
The sharp Occam's razor flashed across, cutting the former to pieces.