Sadly you can't run cQuam and IBOC at the same time, and mono station have to cut their audio back to 5KC. A lot of IBOC receivers will decode Quam, but most have narrow filters so their sound quality isn't up to the old standard.

If you have a nice wide receiver and tune in a station running IBOC instead of getting some nice treble response you'll hear the hash. Yes, they are actually interfering with their own signals as well as making their audio sound worse on both the analog form AND the far too compressed to sound decent digital form too. Go fugue.