The howling I understand. Mine starts that noticeably at ~4k miles into a rear Bridgestone, when you initiate a lean into a turn. It has to do with the shape of the tread...the treadblocks feather a bit, leading to the moan/howl. If you lightly rub your hand along the tire tread, you can feel it.

You guys are my heroes on mileage for sure. I get 8K pretty religiously on a rear Stone (assuming I don't find a nail first). 11k or so on a front. That said, I do replace mine well before it gets to the wear bars. Maybe I need to work on smoothness more.