cutting dead air and eliminating background hiss

Make sure you save the wave file after doing the MP3 conversion, this way you can go back and make changes.

The his can be removed with noise removal plugins in a good wave editor. but it will affect the wave file. It is better to alway try to eliminate noise up front. as far as gettin grid of dead space just click and slide the wave file to the left. unclick the snap to grid feature and it will slide easier.

Another idea to deal with the dead space is to fade-into the piece or maybe just cut it somehow or drag it into place somehow. Fade-ins can work good on pieces with hiss too--you hear the hiss the most at the start or end up the piece due to your noise-to-signal ratio. You basically hear more hiss than song until the song gets going and at that point--it's harder to notice the hiss. So you can fade-into and out of a piece to help it "look," or sound like it's not as bad as it is! :)

Noise gates are supposed to help. Maybe limiters, compressors can function similar to that.

I found the following on another forum and copied it so it might help in some situations

I use Goldwave, In Goldwave I find I can select a portion of the recording that just has the noise, copy that selection to the clipboard, then use Noise Reduction, selecting "Use Clipboard", FFT=12, Overlap=95, Scale=100, and the noise reduction is excellent. Just the noise is removed, but the music tonality is untouched. This works best with low level hum and hiss. For instance, when dubbing a tape to a wave file using Goldwave, I can then sample the tape hiss, use NR and completely remove the hiss (total silence) but the music sounds the same, no loss of highs.

Another feature I use in Goldwave is Match Volume to measure the average volume level of my final mixdowns. I shoot for -16db. If the level deviates more than .5db from that, I remix and create a new mixdown to get the average level I want. That way all tracks on an album sound the same volume level.

Never tried audition, but i did a couple songs the other night using goldwave on these settings and i got almost perfect results, the hiss was gone and the tracks did not lose their dynamics. I would love to try audition, but that dude is a lot of cash, Gold wave is free to try and only $55 to buy.