When it comes to notifying people, you have many targets to consider, and all are important. Let’s look at a shooting/hostage event as an example of how all the moving parts must mesh:
- People on campus could be in immediate danger, depending on their location. While a cell-phone or other mobile messaging system may reach them, it still takes precious seconds to find a device and either hear or read a message. Time can be lost as “connected” people need to interpret and pass along instructions and warnings to “non-connected” people. Everyone will benefit from hearing and understanding the same message at the same time. Up to one-third of the people on a campus at any given time may not be part of the university; that number could be higher during a major event, such as a football game.
- People in campus buildings can get the same message at the same time through an integrated system of indoor speakers, graphic displays, electronic signage and messages delivered via the Internet and mobile devices. They will know to stay where they are or where to find a safer location.
- People not yet on campus will hear the loudspeaker announcement if they are in hearing range, and that will help them make better use of voice and text messages delivered to their mobile devices.
- Emergency responders from various agencies converging at the scene will be able to serve more effectively by knowing what instructions are being given to the public and other responders. Police, fire and other first responders can get that information from their own radios, with loudspeakers becoming an effective back-up if radios fail. This is why voice must be clear and intelligible. The minimum standard is that 50 percent of words be understood — a 0.5 level — but that’s inadequate. Being 70 percent understandable — a 0.7 level — is much better.
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4. Use Prerecorded Messages in Multiple Languages
You could give yourself an “incomplete” if your emergency mass notification system doesn’t have a component that can play pre-recorded warnings and messages in several languages. These features help to save time and avoid confusion.
Some systems available on the market today provide a large library of warning tones and prerecorded voice messages that cover all types of emergencies. It should b
e a matter of policy and procedure to determine the warning tones, messages and languages you will need, and you can use a system of folders, all accessible within your message-delivery devices’ software, to group messages and to sequence when to play them back.
Here are three important requirements for the message-delivery system you select:
- The system should be able to work with a computer at the command center and from a wireless handheld device so that you can change messages to provide more up-to-date information.
- The system should allow you to switch from pre-recorded messages to live messages as your emergency-response needs change, and you should be able to make those live announcements from the command center or from the field.
- The system should have easy-to-use capabilities to combine messages from its library and record, and play new messages as conditions require.
5. Have the Ability to Access Your System from an Off-site Location
The time and conditions of a campus emergency may require the activation of the emergency mass notification system from a cell phone, landline or off-site computer. Further, you may need to change messages for your loudspeakers and other notification platforms as events unfold. Make sure that the system you specify has this capability, and that your policies and procedures definitively state who has access to the system and how it is to be used.
One final point to keep in mind is that integrating all the components of a comprehensive emergency mass notification system is highly feasible. Specifying and installing a system does require attention to many details, and it does require clear policies and procedures to activate the system and use it effectively to protect lives and property. But it can — and should — be done.
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9 Technical Factors to Consider
1. Speaker arrays for fixed systems should have a full 360o range to ensure coverage in all directions
2. Each fixed-system speaker array should have a minimum effective range of up to 800m in diameter
3. Speaker frequency response should range from 400 Hertz (Hz) to 7000Hz, for clarity for the human ear. Power and intelligibility go hand-in-hand in emergency mass notification.
4. Harmonic distortion should be less than 1 percent at full RMS power
5. Wireless UHF transmission systems have severe limitations. Because of legal restrictions regarding the very narrow frequency band spread allocated for UHF transmitters for emergency notification systems, high quality voice transmission cannot be technically possible. The baud (transmission) rate is too low, and the audio band width of the channel is limited to a total of about 2000Hz audio frequency response at best. Systems that depend on licensed UHF transmission can work well as digital controllers for setting off sirens, or reporting of unit status, etc. Because of the narrow frequency limitations of the transmitters, the loudspeaker drivers included with those systems are also not designed for the wider fidelity required for quality intelligible voice audio.
6. Have adequate battery backup for four hours of continuous operation
7. The system should be able to handle multiple broadcast nodes spread throughout the area to be covered. Each node can have up to four speaker arrays.
8. Outdoor speakers should be ruggedized and capable of operating in a broad temperature range from -30° F (-34°C) to +140° F (60°C)
9. Systems that meet military specifications will be able to withstand most on-campus conditions
Stefan Pollack is president and CEO of IMLCORP located in Marietta, Ga. For more information, visit www.imlcorp.com.
Related Articles:
- Your Mass Notification Cheat Sheet
- Can You Hear Me Now?
- 11 Ways to Relieve Your Mass Notification Headaches
- Solutions to Your Common Emergency Notification Problems
- Ensuring Emergency Messages Get Delivered at Carnegie Mellon U.
