only guessing here but I recently had noise on CDs I had burned and it turned out that it came during the burning process. I have no idea what caused that. Some options here are to listen to the track on your computer and see if you have the same problem as on the CD. If that track is distorted you can try ripping the original to wave and starting over. Hopefully, you will get some advice here that will save you that trouble.

You are probably already aware of this but MP3s can be saved at differnt bit rates. 128 is considered CD quality in some things I have read. I usually save at 192 and sometimes higher since space is not as much a consideration as it was in the early days of computing.