I recorded two devices, one microphone and one telephone, and I accidentally recorded them on the same audio track. Is there any way to separate the two different feeds after they are already on one track? It was a 45 minute interview, tape-sync, and the quality needs to be pristine, however right now, there is too much background noise from the telephone. Oops. Thanks!
If it is a mono track, then no, you’re stuck with the two together.
If it is a stereo track and the microphone is one one side and the telephone on the other (left/right) then you can use “Split Stereo to Mono” http://manual.audacityteam.org/o/man/splitting_and_joining_stereo_tracks.html