I purchased the audio files from the university that created the program. I don't think they sell too many copies... it took about two months and repeated emails to different people to get the order completed (everyone was very nice, but couldn't actually process the order...). The sound files are decent quality and I find them quite useful. However, there is nothing that really links a section of the text with the correct audio file. The audio files come on two CDs. Their website says you can chose to get the files as MP3s, but I was told that wasn't actually an option. Overall, I find s azov handy as supplementary material, but I wouldn't want to rely upon it as my primary learning source.