A tradition I dearly love, Irish sean nos singing, has a natural nasal quality to the singers, but what Iris Dement is doing is not natural old time sound. Her hard pushing up into the sinus doesn't sound natural, it sounds like something she developed as a bad habit and just doesn't know how to stop. Pretty sound is not the point I'm making.... there is a nasal hard push that is very contrived about her singing, not a natural old style sound. Maybe I'll find a sound file link to compare and post later to explain better what I mean.