Need help with audio files causing unity to freeze

Hey, could really do with some help here! Unity will play the scene with my sound once, all good. but when i press stop, and play it again, the sound does not load and as soon as i press play to stop the scene playing, unity freezes and stops responding. I thought the problem was playing the audio on awake, so then I coded it so that it played after the timer I set reached 3f, but the same problem happened. I also thought it might have been a compression issue, so then i compressed the audio file as an .ogg file and had it compress in the memory (before the scene loads). Does anyone have any other ideas? Thanks, Stephanie