I am doing some spoken word recordings with Garage Band and then exporting them to I-tunes. The recordings sound completely different when I play them from Garage Band and in I-tunes. The I-tunes version becomes somehow 'harder' with an almost metalic sound, and also there is a significant 'white noise' background sound that is added when I export it to I-tunes. I tried exporting it with both ACC and Mpg formats but get the same result. Any suggestions?