I received 2 missed calls from this number today, one at 11:29 AM, the other at 11:50 AM.  No messages were left.  Dirsectory states that this is a mobile Cincinnati Bell phone, based out of Hamilton, OH.

This is the number that shows up when someone from Hamilton County calls you.  It is the general informtion line, though when someone calls, they are calling from their direct line, this is simply to protect them from getting unwanted direct-line calls. It could be likened best to a switchboard switch board.

Got three calls within 5 minutes.  I did not answer and they left no messages

I've gotten a few calls from this number.  They wait hang up *after* listening to the answering machine- and you can hear the "hang-up" on the message.

Went through an old blog for project, turned up that foot note.
We were getting prank called from that number in Nov 2007 for what it's worth.
We funneled the (513) 946-9999 number to /anonymous...suffices to say, the calls stopped.