My Building has Two Emergency Tones?

When I am speaking to groups during my emergency training sessions it becomes quite apparent that many staff have no idea, or perhaps really dont care, what the emergency warning tones in their particular building sound like. In Australia, most hi-rise will have a standard two-tone system that consists of an Alert Tone and an Evacuation Tone. These two tones are generally described as a 'beep beep beep' (Alert Tone) and a 'whoop whoop whoop' (Evacuation Tone). Here's my point. There is a distinct reason for two tones and a distinct reason that they are called Alert and Evacuate. The first tone is alerting you to the fact that something somewhere has gone wrong and only when the second tone activates should occupants begin to evacuate. (Of course if you are in imminent danger because the emergency is right there in front of you; you should take whatever safety measures are best) but if you are unaware of what's gone wrong and where, wait for further advice from the building's Chief Warden. You may well be evacuating right into the emergency by failing to listen to instructions.