Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

"What's the matter? There won't be a case, will there?"

Yang Sen can't hear the existence of the case now, so he can finally take a break. If there is a case, then everything will be ruined.

Liu Guodong shook his head: "It's Lao Yuan from the Criminal Police Brigade of the High-tech Zone."

"Yuan Shaokang?"

Liu Guodong nodded. Yuan Shaokang is the captain of the criminal police brigade in the high-tech zone, and he is familiar with the people currently surveying.

"What's wrong? Then something happened to him?"

"It was a previous case." Liu Guodong looked at Lu Chuan: "He came to the bureau for a meeting this morning and heard about Liubai's case."

"I know about Lu Chuan's identification of phone recordings, and I want to ask Lu Chuan for help in analyzing a recording of the case."

Lu Chuan nodded: "That's no problem, just ask them to send the recording over."

"Okay, I'll call him back."

Soon, the Criminal Police Brigade of the High-tech Zone sent the recording over.

"This was a case three years ago, and it was quite a sensation at the time."

Liu Guodong knew about this case, not only Liu Guodong, but also Yang Sen and Lao Bai.

Three years ago, a gang that kidnapped and trafficked children appeared in Haizhou City.

In just three days, there were four reports of missing children.

At that time, this case attracted great attention. Song Jiangguo was appointed as the commander-in-chief, and a special case team was formed in the shortest time.

Of course, the final result of the investigation was also good, and all four children were found.

However, the child was found, and the case was not over.

None of the kidnappers were caught.

"These people may be habitual offenders, their modus operandi is very skilled, and they are very good at hiding their identities."

Yang Sen sighed: "We also participated in it back then. The child was found in an abandoned warehouse."

"After the incident happened, the city attached great importance to it, and all traffic in the city was under martial law at that time."

"The abducting gang had no way to transfer the child, so seeing that there was nothing to do, the gang absconded and the child stayed."

"This recording was taken from the surveillance video in the warehouse where the child was found."

"But the monitoring is actually broken. The camera doesn't work, it can only record the sound."

"The recording inside was also analyzed by a voiceprint identification expert in the neighboring province, but the voice is different from the fingerprint. There is no target comparison for this thing at all."

"So, the case has not been solved until now. The high-tech zone was the main party responsible for the case back then, and the ownership of the case was finally given to them."

The three of Liu Guodong were all deeply impressed by the case back then, and after chatting, the situation of the case became clear.

"Listen first, if you can find something, that would be the best of course."

A few people did not report any expectations.

On Yuan Shaokang's side, in fact, he just wanted to try his luck.

After all, it was not easy to conduct voiceprint identification and analysis in the past, and it was necessary to save it from the next door. Now that Lu Chuan has the ability in this area, it is better to try than not to try.

Still borrowing Lao Bai's earphones, Lu Chuan turned on the recording.

The audio is long and is a conversation.

And it's not just one or two people, it's a conversation between four people.

"Run first, forget it this time."

This is a girl, judging from the intensity of the voice, she should be middle-aged.

The sound cannot accurately determine a person's age, but it can roughly determine a person's age range.

"Why run away? We managed to get these four children, and now we have nothing left."

This should be the voice of a middle-aged man.

"You melon skin, you have a life to earn money but not a life to spend it. Now that the outside is under martial law, this child will definitely not be transported out. If we don't run away and get caught, we will die."

The first female voice to speak.

"Vote, drop the kids, raise your hand if you want to go."

This is three voices, male voice.

"I'm leaving. The traffic outside is under martial law. It's too dangerous for us to bring our children."

This is the fourth voice, female.

After that, the four voices spoke repeatedly and alternately, and the whole process took about 10 minutes.

"Two men and two women, but it is estimated that they are all middle-aged, probably in their 30s."

Seeing Lu Chuan take off his earphones, Liu Guodong talked about the situation back then.

"How did you hear? Did you find anything?"

Lu Chuan Yaoyao head.

He just listened to it once, how could he discover it so quickly.

However, the age of the owner of the voice that Lu Chuan heard seems to be different from what Liu Guodong said.

"Master, you said they are all middle-aged?"

"That's right, I've heard the recording and it feels like I'm a middle-aged person, maybe 40 or [-]."

"When I went to the neighboring province to ask professional voiceprint identification experts to do an analysis, this is also the conclusion."

Lu Chuan shook his head: "There is no problem with the voices of three people, but there is a female voice..."

It was the one who said "I want to go". In the sequence of speaking, the fourth female voice appeared, and there was a problem with her voice.

"Master, when will Yutuyi arrive?"

Before May Day, Qin Yong said to buy equipment, but it hasn't arrived yet.

"Just this week. During the meeting this morning, Captain Qin also said that the instrument is already on the way and should arrive within three to five days."

"Okay, now I can only hear some problems through my ears, but I need to analyze them through the language graph instrument, and I will take a look at that time."

"Okay, but what happened to the female voice you just said?"

"That female voice seems to have had damage to her vocal cords. She should be relatively young, but her voice is damaged and her voice is hoarse. She sounds older."

"But it's not very sure. When the instrument arrives, we can analyze it again. It may be more accurate."

The identification and analysis of voiceprint mainly starts from the two aspects of sound intensity and frequency.

Different people's voices have unique frequencies.

Just like fingerprints are unique, everyone's voice is uniquely recognizable due to the length of breath and the development of vocal cords.

In this recognition, the size of the sound is the most important factor, and the timbre and frequency are the most important.

The timbre is that everyone's voice sounds different, some are hoarse, some are sharp, some are thick, and some are full of magnetism.

In daily life, it is often said that some people's voices are very similar, but in fact, the timbre is more similar.

The frequency is the ultimate difference in distinguishing the voices of different people.

No one's voice frequency is the same, only similar, not the same.

The frequency of human vocalization is as low as 82 Hz and as high as 1200 Hz. Few normal people can exceed this range.

In this range, the frequency band of 800 Hz is the main frequency that affects the timbre. The sound of this frequency band is full and the timbre is pleasant.

The composition of a sound is produced by the simultaneous vibration of different parts of the vocal cords.

Therefore, the frequency of a sound can also be high or low, but everyone's voice is different, and the frequency of the sound will also be different.

Through the analysis of the language graph instrument, it is very intuitive to make a distinction. (end of this chapter)