Don't ya' just love the quantizing noise introduced with all the digital audio stuff these days?
Ironically, my hearing tapers off about 12KHz and my kids about 18-22KHz and they don't hear it. I don't get it, but some higher pitched instruments sounds like a square wave with a fishing hook barb on the side of the square wave edge.
Even CDs have a distinct distorted wave sound on the higher freqs. When I look at the distortion algorithms for waveform reproduction applied to the CD sampling frequency I can understand why. Again, the kids don't hear it!
*completely* cured, maybe there are meetings I can attend to help me stay on the wagon....