I've noticed that when I remove the shrink wrap from new CD recordings, if I use a genuine Swiss Army knife the sound on the CD is enhanced somewhat. If I just use my finger nails, the sound is duller. Also If I open them when I'm sitting on the toilet with my finger nail, they sound falls somwhere between the enhanced and dull sound. I haven't tried using the genuine Swiss Army knife on the toilet yet... I'll let you know how that goes...