disturbing saturday night

Is it a culture thing? We spent 2 years living in a large block of apartments in South Melbourne, and were never disturbed at 3am by the fire-alarms being set off as the culmination of an extremely noisy party. But 2 weeks into living in a smaller block of apartments in Port Melbourne, and we have a sleepless night.
The demographic here is DINKY (dual-income, no-kids-yet) 30-somethings, the other place was 20-something mainly-foreign students. Are students quieter and more responsible than professionals?

At least we can now stop wondering what the speakers are for, built into the ceiling of the bedrooms. The fire-alarm sirens were almost deafening. The fire-brigade were around before we got out onto the street, but then announced "some drongo set off the alarm on the 4th floor, everyone can go back to bed now". And they didn't even offer to tuck us back in....