Day in, day out, and at every stop along the way. I've found that if it has to be repeated more than 3 times at any stop you can hear the request become a little less friendly.
Sometimes the conductor gets louder. As if yelling it into the P.A. is going to make people listen more. Sometimes they just start repeating themselves over and over continuously until everyone has finally clued in. My personal fave is when it gets repeated by someone that sounds like their half asleep. Obviously bored at the fact that they've had to say the same 5 words incessantly.
What I wonder is, why the heck does it take people so long to get the message? Is it just complete disregard for the conductor? Or is it simply too early in the morning for passengers to compute the message? I mean come one folks. Stand clear of the doors so we can get this train to it's destination!