Works fine. Playing around with it I had two thoughts:
1. It would be nice, if the sound played after the whole repair/unrar process finished. It sometimes takes quite some time between the download finishing and the rest being done. But I think you already have this planned.
2. An alternate sound in case the repair/unrar process fails would be convenient. This would alert the user that some additional action is needed. So there would be two sounds, as in DVD-burning software: One for success, and one for failure.