Recently I was sitting next to a 320 pilot (in F on a 3 class domestic, of course) and asked him whether or not the channel 9 switch is part of the pre-flight checklist. What I was getting at was - could a pilot forget about it, or do they purposefully check it and make a decision every flight. He said it was definately not part of any checklist and pilots often forget about it. He said that he will usually turn it on by himself and will turn it on if someone reminds me. The only time he would turn it off is if "it gets a little hairy, like with bad weather". I told him that's the time I like to hear the most . He said that he knows there are quite a few pilots that don't like it, don't like to feel like people in the cabin are watching over their shoulders, and they purposefully turn it off.