Security Dealer & Integrator

NOV 2013

Find news and information for the executive corporate security director, CSO, facility manager and assets protection manager on issues of policy, products, incidents, risk management, threat assessments and preparedness.

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Audio intelligence can tell a camera to record on the sound of a voice, broken glass or a gunshot. It can enact an alarm to sound or alert a business owner to a potential situation. It can even instruct a PTZ camera to focus on a specifc area of a scene and track movement. can be heard (think walkie-talkie). In full-duplex mode, audio is sent to and from the operator simultaneously. When audio is used merely to listen in on a scene or for video analytics, simplex will do the job. If you are working with an operator team and communication with people in the video scene is intermittent, then half-duplex will be acceptable; however, if the use of audio is for visitor management, emergency response or video conferencing, full-duplex is the choice. Remember, though, that while full duplex has the simultaneous audio advantage, it also increases the bandwidth required. the legality of the system — or what's required to make it legal — before product procurement. The Future? Most articles end with a look toward the future of technology and what it'll bring. No need here. The technological marriage of audio, video and access control technology is here and it's a strong one. It's up to the expertise of the integrator to determine if audio is needed and then how to apply it. ❚ Fredrik Nilsson is the general manager for Axis Communications in North America. He has more than 15 years of experience with IP video systems and is the author of "Intelligent Network Video: Understanding Modern Video Surveillance Systems," published by CRC Press. His popular "Eye on Video" series can be found on SecurityInfoWatch.com. To request more info about Axis, visit www.securityinfowatch.com/10212966. Five Best Practices for Installation Once the appropriate IP camera, encoder and/or audio accessories are selected, there are a few other crucial installation and configuration best practices: 1. Audio equipment placement: Although an audio signal can be amplified later, appropriate placement of equipment will reduce noise. In full-duplex mode, the microphone should face away from the speaker at a reasonable distance to reduce feedback. 2. Amplify the signal as early as possible: This minimizes noise in the signal chain. In addition, make sure the signal levels are close to, but not over, the clipping level where audio becomes distorted. Proper gain selection is especially important to surveillance installations. If possible, the gain should be applied as early in the signal path as possible, preferably in the microphone itself. 3. Apply appropriate signal processing technologies to improve audio quality: Audio quality can be improved by adjusting the input gain and using different features such as echo cancellation and speech filter. 4. Select the right codec and bit rate: The type of codec and bit rate selected will affect audio quality. In general, the higher bit rate, the better the audio quality. 5. Understand legal implications: States and countries have different restrictions on the use of audio and video surveillance. Check with the local authorities about Immediately available in 11 contact styles, High-Security switches create the ultimate security protection for Jewelry Stores, Document Vaults, Gun Safes and other high value targets. Request information: www.securityinfowatch.com/10215295 www.SecurityInfoWatch.com | SD&I; | November 2013 39

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