Not able to get edited recording to play edited version in Multitrack

Hi!  I am very very new to audition and podcast editing with limited knowladge of it all.  But I am here to learn.  I am on a MacBook and audition is up to date.  My problem is this.  I have fine tuned edited a file using both waveform and spectral display.  It sounds great.  When I open the file by itself, all my work is done.  But, when I import the same file into a multi-track Mixdown and play it, the file goes back to how it sounded before I fine tuned it using the spectral display and it does not sound good.  How do I get the edited file to play the edited version in Mixdown?  Thank you for any insight.