This is a really simple set of steps to duplicate one channel of a stereo recording to the other channel, but for the life of me, I cannot ever seem to remember it so I am going to write it dow so I can refer back to it.

My problem is that I use a Zoom H4N Portable Digital Recorderand high quality microphone to record my IEEE Computer Computing Conversations podcasts and so I end up with a single channel in a stereo track with the other channel completely silent.

Here are the steps to duplicate the track with sound to the other track so both channels are identical:

From the track drop-down by the file name "Split Stereo Track

Select the entire upper track by double clicking and Copy (i.e. Command-C)

Move the cursor to the very beginning of the empty track and Paste (i.e. Command-V)

Select both the top track and bottom track (Using click on one track shift click on the other track or Command-A)

From the track Drop-down by the file name select "Make Stereo Track"

Surprisingly simple yet hard for to remember if I do it only once per month.

This web site helped me figure it out in the first place – http://chacadwa.com/foh/mono-to-stereo-in-audacity