New to AUDITION and am getting distortion and echo when playing back the file

Hi - I'm new to Audition and I had it all working well two days ago with my Presonus io24 interface and Heil PR 40 microphone. I recorded in Audition and it played back well. Now --- the recording seems to work well -- but when I play back the file, I get an echo-y distorted playback on that file. I've checked EDIT and PREFERENCES and everything seems to be chosen correctly re equipment. I'd appreciate any help. THANKS