Diana had(has?) a hearing impairment from a bad reaction to antibiotics that were prescribed to her when she was a toddler. She says her hearing has improved now (not sure how), she's a pretty good ice dancer (not P/C level, but still very good), so maybe that's so.
Tiffany unfortunately got meningitis (inflammation of the brain) a couple of months back and was in hospital for a while. She's only recently been able to train again, it looked like she was quite dizzy during the FD, so I guess she hasn't completely recovered, but she doesn't seem to be in danger or anything.