Automatically mute "inactive" audio in double-system recording of dialogue for cleaner sound?

I edit long form conversations between two people, individually recorded onto two sound mixers. The unfortunate thing about placing the two dialogue audio files on top of each other is that it creates a kind of echo. Right now, I have to manually raise and lower the volume of the two sound tracks, depending on who is speaking, but this is a tedious process:

Is there a function in FCPX that automatically mutes sound tracks when the sound is "inactive" or low? This would really be helpful in my situation.