I often get a kick out of people that love to talk and talk and talk. Eventually, some people just take out their phones and start texting. Others take to opportunity to re-fill their coffee cup. The funny part is that the people that love to talk don't even seem to notice this!! I figure they are so wrapped up in what they are saying, I think the room could pretty much empty out, and they'd keep talking.
But back to the OP's concerns. I have found that you don't hear many people repeat their stories in larger rooms. Seems there's a lot more people coming and going, so you hear a lot of different stories in that situation. John