Have you ever been trimming along and encountered a "blip" of audio that makes the cut not work? Often it's so quick that it's difficult to tell whether the problem is on the outgoing shot or the incoming shot. Here's a quick way to find out, and avoid all the trial and error:

 
1 - Enter TRIM MODE at the transition you want to fix.

 
2 - Click the "Play Loop" button

 
3 - WHILE the looping is happening:
      A - ON YOUR KEYBOARD, press the "Go To Mark In" button
            Now, the looping will continue, but only over the OUTGOING shot.

      B - ON YOUR KEYBOARD, press the "Go To Mark Out" button
            Now, the looping will continue, but only over the INCOMING shot.

Using one or both of these will help you to easily determine where the problem frame or frames of audio are.