I imported 15 different wma files into 15 separate tracks in Audacity. Each file sounds distorted, you can't make out the music, or even tell what your listening to. I have never had this happen before.
It won't be audacity - just a wma variant - bit rate, bit depth that your codecs don't recognise. Do you know the .wma spec? I presume windows plays them OK, but Audacity doesn't? Audacity will allow mismatches of sample rate and bit depth. I'm not sure it is happy with 32 bit floating point files in some formats.
I selected, select all on audacity, and then align all tracks end to end. Now every track sounds normal. I was not aware I had to complete these steps to listen to normal audio tracks.