"What's wrong? There won't be a case, right?"
Yang Sen can't hear the existence of the case now, and he can finally take a break. If there is a case, everything will be ruined.
Liu Guodong shook his head: "It's Lao Yuan from the High-tech Zone Criminal Police Brigade."
"Yuan Shaokang?"
Liu Guodong nodded, Yuan Shaokang is the captain of the High-tech Zone Criminal Police Brigade. , and are relatively 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 the Liubai 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 a case.”
Lu Chuan nodded: “That’s no problem, just ask them to send the recording.”< br>
“Okay, I’ll call him back.”
Soon, the High-tech Zone Criminal Police Brigade sent the recording.
"This was a case three years ago. The case was quite sensational 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 task force was established as soon as possible.
Of course, the final tracing results were also good, and all four children were found.
However, the child was found, but the case was not completed.
No one in the trafficking gang was caught.
“These people may be habitual criminals. They are very skilled in committing crimes and are very good at hiding their identities.”
Yang Sen sighed: "We were also involved back then, and the child was found in an abandoned warehouse."
"After the incident, the city attached great importance to it, and all traffic in the city was under martial law."
“This trafficking gang had no way to transfer the child, so when they saw that nothing could be done, these guys absconded and the child stayed.”
“This recording, It was taken from the surveillance video in the warehouse where the child was found. "But the surveillance was actually broken. The camera didn't work and could only record sound."
"The recording inside was analyzed by a voiceprint identification expert from the neighboring province, but the voice was different from the fingerprint. There was no target comparison in this thing."
"So, the case has not been solved yet. The High-tech Zone was the main party responsible for the case, and the ownership of the case was finally given to them."
The three of them were deeply impressed by the case, and while chatting, the situation of the case was explained clearly. .
"Listen first. If you can find something, that would be the best."
None of them had any expectations.
Yuan Shaokang actually just wanted to try his luck.
After all, it was not easy to do voiceprint identification and analysis in the past. You had to go to the next door to save it. Now that Lu Chuan has the ability in this area, it is better to try than not to try.
After borrowing Lao Bai's headphones, Lu Chuan turned on the recording.
The audio is very long and is a conversation.
And it’s not just one or two people, it’s a conversation between four people.
"Run first, let's forget it this time."
This is a girl. Judging from the strength of her voice, she should be middle-aged.
The voice cannot accurately determine a person's age, but it can roughly determine a person's age range.
"Why are you running? We got these four children with great difficulty, and now they have nothing."
This should be the voice of a middle-aged man. "You idiot, you have your life to make money but not to spend it. Now that martial law has been enforced outside, this child will definitely not be able to escape. If we don't run away and get caught, we will die."
The first female voice to speak.
“Vote, leave the kids behind, raise your hands if you want to leave.”
These are three voices, male.
“I want to leave. The traffic outside is closed. It is too dangerous for us to take our children.”
This is the fourth voice, a female voice.
After that, four voices spoke repeatedly and alternately. The whole process lasted about ten minutes.
"Two men and two women, but it is estimated that they are all middle-aged, probably in their thirties."
Seeing Lu Chuan take off his headphones, Liu Guodong talked about the situation that year.
"How did you listen? 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 seemed to be different from what Liu Guodong said.
"Master, you said they are all middle-aged?"
"Yes, I heard the recording and felt that they are also middle-aged, probably in their thirties or forties."
< br>
"I went to the next province to ask professional voiceprint appraisal experts to do an analysis, and we came to the same conclusion."
Lu Chuan shook his head: "There is nothing wrong with the voices of three people, but there is a female voice..."
The one who said "I want to leave". The fourth female voice that appeared in the sequence had a problem with her voice.
“Master, when will the Yutu instrument arrive?”
Before May Day, Qin Yong said he wanted to buy the instrument, but it hasn’t arrived yet.
"Just this week. During the meeting this morning, Team Qin also said that the equipment is on the way and should arrive in three to five days."
"Okay, now I just hear some through my ears. Question, but the specific analysis needs to be done through the speech chart instrument, and we will take a look at it when the time comes."
"Okay, but what happened to that female voice you just said?"
"That female voice? , it seems that her vocal cords have been damaged. She should be relatively young, but her voice is hoarse due to the damage, and she sounds older."
"But I'm not sure. I'll analyze it again when the equipment arrives. Might be more accurate.”
The identification and analysis of voiceprints mainly starts from two aspects: the intensity and frequency of the sound.
The frequencies of different people’s voices are unique.
Similar to the uniqueness of fingerprints, each person’s voice has unique recognition due to the length of breath and the development of vocal cords.
In this recognition, the size of the sound is the least important factor, while the timbre and frequency are the most important.
Tone color means that everyone’s voice sounds different. Some are hoarse, some are sharp, some are deep, and some are magnetic.
In daily life, it is often said that certain people's voices are similar, but in fact, the timbres are similar.
The frequency is the final difference in identifying different people’s voices.
No one's voice frequency is the same, it can only be similar, not the same.
The lowest frequency of human voice is 82 Hz and the highest is 1200 Hz. Very few normal people can exceed this range.
In this range, the 800 Hz frequency band is the main frequency that affects the timbre. The sound in this frequency band is full and the timbre is good.
A sound is composed of different parts of the vocal cords vibrating simultaneously.
So, the frequency of a sound can also be high or low, but everyone's voice is different, and the frequencies that make up the sound will also be different.
Through the analysis of the speech chart analyzer, the identification can be made very intuitively. (End of this chapter)