Whilst screen-capturing a webcam I’ve accidentally recorded 2 soundtracks, as I had the cam open in another browser, hidden. There’s about half a second, if that, between the two tracks.
I was hoping the Audacity could detect the second soundtrack and remove it, but Google hasn’t found anything on-topic, I’m just asking here so’s to leave no stone unturned.
No… or I should say, yes it’s impossible. 'You can’t un-fry an egg or un-bake a cake, and you can’t un-mix sound."
You don’t two separate soundtracks, you have one soundtrack with an echo, right?
… If you had a “clean” copy of one or the other, you could (potentially) subtract one out. But, if you had a clean copy you wouldn’t have this problem.