Not exactly a propos of your last post, but the noise reduction is not a magic bullet. Like everything else relating to digital audio it is a tool that rewards experimentation and patience. A person here brought me some tapes made from a Radio Shack telephone mic onto a cheap cassette recorder on long distance calls during which he interviewed his parents in Kentucky. During much of the tape it was not obvious that someone was speaking! After LOTS of trials, EQ, re-trials, and I don't remember what all, we got an acceptible result where it sounded like a human being speaking in intelligible English.
Don't think you'll get it the first time. It took me 3 evenings until this person (a retired history professor) finally found in another person what he thought **I** was, to wit, a surrogate graduate student who would do all the hard stuff for him for him for free! I am proud of the fact that I didn't save any of the work I did, or he'd be going around town explaining to everyone about how HE cleaned up the tapes...
But I digress. Give me music any day.