Thank God and to these forums I solved it!
I went to my hard drive "Macintosh HD" then
and moved "com.apple.iMovieApp.plist" to the trash, then emptied the trash can. Opened iMovie and everything was reset.
Then opened the project I was working and everything was fixed.
All the audio files were playing back with the adjustments I had made earlier.
By the way my "Cosme422" is my home folder. Yours will be called something else, what every you used when you setup your computer.