[SN95 5.0]

first of all, my stang is a 94 gt with a t-5. my problem is that whenever i am in neutral with the clutch all the way out, i hear a a noise that almost sounds like a squeaking belt. when the clutch is pushed in slightly, the noise changes a little, and when it is pushed all the way in, there is no extra noise. why is my car making this noise?