Groo,
Of course if the alarm rings your out of there - Current standards (at least here in NYC) have eliminated the "Macy's tone" (aka alert tone) and you ONLY get an alarm on the fire floor, and one floor up - aka a full "active" alarm - you hear an alarm on your floor, you are IN the active fire zone - get the heck out!!!

On floors not "involved" you will get NO alarm, not even the alert tones

You hear an alarm - you GO - don't make the floor wardens and/or searchers look for you. Before you open any doors btw - check them with the back of your hand to see if they are hot - and almost all stairwell doors also have a window - check for smoke - there will always be at least 2 stairways off of each floor - if one is blocked, try the other