Mike's right, there's no calibration information on this, but it's not without merit.
I have a significant notch loss at 12k. and that corresponds to the professional hearing test I had a couple of years ago.
I think this is pretty darn good for a 49 1/2 year old...
this test doesn't show it, but I also know that above 16k I pretty much roll off the chart. I can't hear 18k+ at all.