Well, that question REALLY depends on where do you live and who do you ask.
But no, you were right. And during this month of Ramadan, at around 6 pm everyday there's always a preaching. At around 3-5 AM, there's a 'call' (which generally means someone wandering around the block, hitting drums / bottles / whatever) before fasting, followed by another call for prayer / sholat.
And wrong, too, during the other months, the call for Maghrib (the ones around 6) were rarely voiced, unless you lived near a mosque. You'll hear it on the TV, though.
A lot of my friends, being non-Muslim, found it extremely obnoxious. I myself don't have anything about it, though.