Surveillance video with sound. The quality factor

Despite the breakthrough of technological thoughts, the theme of sound is not clear in the video surveillance market. The situation is such that the sound quality in video monitoring is considered to be an unimportant function. Audio system manufacturers do not pay enough attention to CCTV systems, and video recording vendors do not pay attention to the sound segment. As a result, the sound quality in video surveillance is often unsatisfactory.  

The relevance of sound in the security system

One of the mechanisms of video control can be sound recording. Not all cases require sound. But when it comes to security in shops, restaurants, banks, hotels, business, cameras with high-quality sound are necessary:

• at cash zones;
• workplaces of customer service managers;
• in children’s lounges.  

The purpose of CCTV with sound in the above places is:

1. To raise situational awareness. For example, suspicious noises and sounds may indicate the presence of strangers.
2. To prevent theft and fraud (by staff and customers).
3. To identify conflicts, disputes, manifestations of aggression at an early stage. 
4. To investigate events.  
5. To gather trial evidence. Read the article “Can a video record be evidence in court?”
6. To improve the security of the facility in general.

Do you know that a modern camera with sound for video surveillance cannot only see and hear but also talk to the filmed people? It’s about a network loudspeaker.

USE CASE: For example, you need to control large objects and their perimeters.  Before, you had to integrate the loudspeaker and security software. When an intruder enters the camera’s field of view, a warning recording is automatically activated: “CCTV is in operation in this area. You’re breaking the rules. Leave the area.”

This solution has a high degree of psychological effect on the attackers, allows to save the company’s resources and increase the return on investment.

There is also the technology of aggression detection through predictive video analytics.

USE CASE: The use of “smart” video analytics can distinguish increasing speech volume, raising tone, detect fear and/or pressure in a person’s voice. When a specific sound pattern is fixed, the security system triggers alerts to the operator. This provides a rapid response to prevent acts of aggression.

Sound relevance as an optional function for business

Video surveillance with sound enables a business to reach a new communication and interaction level with customers and employees. The following activities facilitate it:

• reproduction of marketing content in certain zones;
• setting up background music to attract customers;
• copy operational messages in routine and emergency situations;
• recording and analyzing employee’s conversations with the customer to improve service;
• control of production processes.

The main advantage of network sound is cost-effective scalability, which allows you to update/add equipment to the video surveillance system when it needs change.

Mics technology

The use of the microphone in video monitoring systems is done in two types:

1. Video equipment with a built-in audio element.

2. Microphone as separate equipment, used additionally.

Pros and cons of built-in and individual microphones

 Table of advantages and disadvantages of built-in microphones:

Advantages	Disadvantages
There is no need for additional installation and additional attachments, cables, hulls for non-hulled microphones.	Low sound quality (medium to unsatisfactory).
Aesthetic appearance	Capture limited sound space (it’s smaller than a video camera view)
	No adjustment.
	Unknown characteristics of the built-in microphone.

Table of the pros and cons of separate microphones in the CCTV system:

Advantages	Disadvantages
The ability to choose any model of the microphone.	The need for additional cables, attachments and other elements.
Use of multiple microphones (if it is necessary).	Investments.
High sound quality.	The need for a power source.
Microphone installation does not depend on the location of the camera.	A remote control is not possible.

CCTV cameras with no sound or sound problems are deprived of competitive advantage.

Results

Video surveillance and sound are rational solutions to ensure a high-security level at private homes and high-traffic commercial buildings. Also, the video’s audio helps to solve marketing and business problems, such as optimising and controlling work discipline and improving service.