I heard it in Bosnia-creepy as hell. Made me think of a goat being strangled.
In Mosul you could hear dozens of mosques blasting it all at the same time, from all around you.
In Baghdad, during a big Battalion operation, my Platoon was set up in a house directly across the street from a mosque when they blasted the call to prayer for about a solid 45 minutes. It NEVER lasts that long, so we figured they were just trying to annoy the crap out of us. It worked.