i have got a rubbing sound on a radio transmitter mic and i have put the offending track into soundtrack pro. how can i set a top and bottom parameter to eliminate the excessive sound?

Removing sporadic noise from an audio track is really tough to achieve in any audio editing program. The best thing to do is to remove it with some creative editing; by eliminating the parts of the sound with the noise altogether.

If the noise is more of a constant sound, like a hum or a buzz, then SoundTrack Pro (and some other audio editing programs) have features to remove this noise from the rest of the track.

The trick is to find a part of your audio track where you can only hear the noise. Then you need to sample that noise by setting a "noise print". Highlight the part of the waveform with the noise, and in the top menu click on "Process --> Noise Reduction --> Set Noise Print". Once you have a sample of the noise, then highlight the portion of the track (or 'select all' to remove it from the entire track) that you want to remove the noise from. Then click on "Process --> Noise Reduction --> Reduce Noise". Make the adjustments as needed to remove the noise, while maintaining the integrity of the original audio.

Again, this isn't a miracle tool. It works best for soft noises that don't imped the sound too much. Just like photoshop, it will only go so far to saving an audio piece.

Good Luck!