The short answer for the test is that the signaling device would fail to operate.
A "Signaling Device" in this context is engineering-speak for a fire alarm device that is used to "Signal" the occupants of the building that a fire has been detected. The most common devices would be horns and strobes. Included in the signaling device category would be chimes, bells, and speakers.
Another way of describing these devices is "Notification Appliances". Notification appliances are connected to a Notification Appliance Circuit (NAC).
All of the conventional devices except the speakers have a diode inside them to block (prevent) electrical current from passing through them in the wrong direction. Conventional speakers have a capacitor inside them to prevent DC electricity from ever passing through them, while the capacitor allows audio to pass through.
Addressable notification appliances are always polarity sensitive. They will not work at all if the polarity is not observed.