I didn't know you could do that with Audacity, I still have some old cassette tapes from years ago. With Audacity I could redo them and burn to disc then or convert to Mp3. That would be good to do.

Oh yes! You can get rid of popping from records, hiss from tapes, and other undesirable noises from whatever you don't want in the recordings. You can increase the intensity (if the original sound is too loud and distorted, the crests and valleys in the waveform had been clipped, there isn't much you can do with it.) To be able to work with analog stuff like this in Audacity you need to have your computer's audio settings according to instructions, otherwise it won't work. When you see waveforms and the meters responding to your speaker's sounds, you've got it right. You can then export the recording to one of several formats if you have the codices for them. I use mp3.

I haven't used Sound Forge. This came about on Chat because I wanted to change my accent on video, a thick Devonian accent doesn't sound too good.

I only know the basics but learning the more advanced stuff will be really handy.