CHAPEL HILL -- The University of North Carolina will test its emergency siren system at 11:30 a.m. Wednesday. The Alert Carolina system is made up of four sirens, which are located in four different areas on campus.

Officials stress that the alert is only a test and the sirens will normally only be used in a life-threatening situation, such as an armed and dangerous person on campus or a tornado.

UNC's sirens will also broadcast brief announcements with instructions such as seek cover immediately.

Earlier this month, North Carolina State University tested its Wolf Alert siren system. It uses a series of tones and voice commands to tell students about any emergency situation on campus. Both universities consider the sirens a first line of communication in the event of an emergency.

In a real emergency, not only will the sirens sound, but both schools will also send text messages to those who have signed up to receive them.