You can swap the channels in a stereo audio clip in the Timeline window. You would typically do this if the channels were incorrectly recorded left-to-right.
To swap the stereo channels in an audio clip:
Select an audio clip in the Timeline.
Do one of the following:
Choose Clip > Audio Options > Swap Channels to reverse the channels.
Choose Clip > Audio Options > Normal to restore the orientation of the clip's stereo channels.