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The newspaper of The Johns Hopkins University April 21, 2008 | Vol. 37 No. 31
Sirens and PA System Being Installed, Tested at Homewood

The sounds of sirens are expected to be attention-grabbers on the Homewood campus this week — and that's a good thing. They're part of the installation and testing of a new alert initiative, which includes a public address system.

"There's no single technology or device that can reach out to everyone at once. That's why we're applying a multitiered approach," said Edmund Skrodzki, executive director of campus safety and security at Homewood. "We already have text messaging, broadcast e-mail, telephone emergency alerts, a Web page and bullhorns. The sirens are a very effective way to alert people who are outside on campus and in areas contiguous to the campus. They're intended to alert the community to an event that can pose an imminent threat. Now we have a very well-rounded system."

The equipment, made by Whelen Engineering, is to be assembled on Tuesday and installed on Wednesday at Garland, Whitehead and the Recreation Center. Each device will be tested for two or three seconds to ensure that all connections have been properly made. On an ongoing basis, the system will do a silent self-test once a week and will be tested live, along with the Johns Hopkins Emergency Alerts text-messaging system, three times a year: once each semester and again in the summer.

The sirens have two distinct sounds. A high/low warning tone indicating imminent danger would go out for one minute, and then the PA system would broadcast a prerecorded message. The PA system would broadcast sequentially — Garland, then Whitehead, then the Recreation Center — to assure that the messages could be heard clearly. The siren's other sound, described as "an air horn discontinuous tone," would broadcast for 30 seconds to indicate an all-clear.

After the system is installed, the Campus Safety and Security Web site,, will have more information, including sound clips.


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