Audio monitoring or become a new highlight of the security industry

Although video surveillance can meet the application in most occasions, sometimes the combination of audio and video is the most perfect. There are not only pictures but also sound cooperation in order to maximize the purpose and requirements of monitoring. More and more security projects are in urgent need of clear and realistic video and audio synchronization monitoring systems. Audio monitoring has become a new bright spot in the security industry.

Speaking of audio monitoring, Xiao Bian remembered the earliest security system in the Palace Museum. In 1959, the “Golden Book” of the Forbidden City was stolen, which triggered the development of the security of the National Palace Museum. In 1962, the thieves Sun Guofan vanished into the Treasure Museum when he was still in the dark, and he was captured on the way back. The breach of the theft case benefited from the simple security monitoring system at that time.

In fact, the domestic security system of the 1960s was dominated by listening systems. Early monitoring systems used transistors to determine if sounds were occurring. By the 1970s, most began monitoring systems using transistor circuits. During this period, the surveillance system also slowly developed.

However, with the continuous advancement of security technology, video surveillance has made great strides, and audio monitoring has slowly been "cold." For the reasons, the following two points may occupy a more important position:

First, since security has always been regarded as a "mysterious" industry, audio monitoring may involve personal privacy issues. For example, some sensitive things privately talked about if "accidentally" are recorded, and monitoring data are not properly kept Caused privacy leaks. Public video surveillance, the country has relevant laws and installation specifications, implementation of legal protection. Although there is no essential difference between audio monitoring and video surveillance, there is no explicit provision that hinders its development.

Secondly, audio monitoring has been “tethered” and has caused its development to be ignored. For a long time, the development of audio monitoring technology has been slow, and the sound transmission itself will be affected by the environment, resulting in difficult noise processing. Since vocals and noise are easily conflated after amplification, audio monitoring does not achieve its purpose and meaning even if it is noise that is picked up by pickups. Pickup noise reduction usually needs to solve two problems. One is to reduce noise from the circuit itself and the other is to reduce interference from ambient noise. The noise of the circuit itself is relatively easy to solve, and the environmental noise problem is more complicated and difficult to solve. Low-level environmental noise can be automatically monitored by noise and feedback suppression. This technology can suppress some of the ambient noise. However, in strong noise environments such as highways, DSP noise suppression must be used to achieve higher requirements. At present, the most advanced speech noise reduction algorithm can only reduce noise by about 20dB in the case of ensuring less distortion. The immaturity of technology has also led to the difficulty of audio monitoring in the application market.

At present, audio monitoring has been widely applied in the public security and financial sectors. Of course, different areas of the environment also have different requirements for pickups. Take the Henan Provincial Public Security Supervision System as an example. This project can be roughly divided into four parts. The first is the service hall, including the traffic police, immigration, law and order, letters and visits, vehicle management. The halls, these places are characterized by a large area, empty and noisy, which requires a microphone with high sensitivity, wide range, strong anti-noise performance; for the outdoor environment, it is mainly wind noise, road noise interference, pickups defense Strong dust and moisture resistance requirements; while the relatively small area of ​​the indoor environment, the echo is larger, we must take anti-echo technology; for a special quiet environment, requires the ability to hear very subtle sounds, such as the public security supervision of the trial and * In the room, slight sounds can be collected at the first time. This requires that the sensitivity of the pickups must be very high and the sound effects must be achieved.

In fact, at present, many public security, police, and traffic law enforcement vehicles do not have audio monitoring. In the event of an emergency, they often lack strong evidence of sound. When law enforcement officers go out on patrols, they often encounter various disputes or even violent incidents. If law enforcement vehicles install audio and video recording systems or wireless transmission equipment, they can play back afterwards, and they can also facilitate timely command of the situation. In this way, the incident “Shenyang peddler Xia Junfeng stabbed to death” may be avoided.

Fortunately, audio surveillance as a branch of the security industry in recent years, the rapid development of the current show has been unprecedented vitality, people began to pay attention to the needs of the eyes began to see and hear the demand for high-definition audio and video surveillance. Ercong Mingming, when the security monitoring system is no longer just the world of the screen, perhaps security can better play a pre-warning, post-mortem evidence.