These systems rely on microphones and video cameras and, best of all, they can easily be set up by any home computer hobbyist (although companies abound that will set them up for you).
If you already have a computer, perhaps you've been introduced to the world of web cams. These are video cameras that are typically placed on top of your computer facing you. They take continuous images.
Using appropriate software that's simple to install and operate, you can take the video signal from the web cam into your computer and using an Internet connection, send it to another computer anywhere in the world. Thus, two people who are appropriately outfitted with web cams, software, computers, and an Internet connection can see each other in real time. Additionally, a microphone can be connected to the web cam, which will then transmit not only video, but audio feed as well.
Today there are web cams operating 24/7 around the world. Try a search engine using the word, "Web cam." You can use your Internet access program, Explorer, Netscape, and so on, to easily access these and see continuous views of the Eiffel Tower, the Golden Gate Bridge, or whatever someone happens to be putting up at the time.
The applications of this for home security should be obvious. Web cams (which can be purchased for under $30) can be situated at critical points in and around your home. They can be connected by wires (or can be wireless, although the cost is increased) to send the A/V signal to your computer.
Your computer can be connected to the Internet and can broadcast a continuous signal to another computer anywhere in the world, which can then look in and listen to your home. Alternatively this system can be connected to a variety of sensors around the home, which activate it only when there is an intrusion. Thus you can be alerted when there is movement in your home. You can actually see what's happening. And then you can take appropriate action.
Most web cams operate on visible light. Hence, they are blind at night. However, you can use sensors that will turn on the lights when motion is sensed. Or you can use infrared web cams (and infrared illuminators) that don't need any visible light at all.
Advantages of A/V Surveillance Systems
- You can see and hear what's happening at your home, even when you're far away.
- If you already have a computer and Internet access, they can be inexpensive to install.
- You can do it yourself.
Potential problems with A/V surveillance systems
- They depend on a constant Internet connection, which can frequently be down and is expensive to maintain.
- Your computer must be on all the time, computer glitches might take down the surveillance.
- You or someone must monitor the system (unless you pay for a security company), and you're likely to often be unavailable.
- Power outages can easily take out the system.
- A burglar can simply cover up the camera and mike, thus eliminating the surveillance, although this in itself can be an alert.
Also any computer that's online all the time is subject to invasion from hackers. While they just might want to see what you're watching, they also might have thievery on their minds. A good firewall, updated operating system, and virus/spy protection will help.
A/V System and Security Company For what is usually a substantial amount of money, many security companies will outfit your home with A/V surveillance to their offices. Instead of your watching, they watch. If there's a problem they can send out their own cars, or notify the police.
Additional Applications It's worth noting that one additional application of an A/V surveillance system can be for monitoring someone such as a baby or elderly person. These can be set up around the house. Additionally, there are personal systems now available for the elderly that have an alert system located conveniently in the house, or strapped to a wrist for example, that will alert a security system or automatically call a relative.
