A Fast Way to Work with Audio Separately

Software: Apple FCP X

If you want to expand the audio from the video being used in your timeline, a double-click on the audio waveform is all that is needed. This allows you to edit the audio and video separately, while still keeping in sync. You can also use the keyboard shortcut Control + S, or you can choose View > Expand Audio/Video Clips > For All to expand multiple selected clips.