Some of the best known listening or audio packs for learning Japanese include those published by Pimsleur. But commercial audio learning aids, in my opinion, are not necessarily the best out there. Pimsleur can be quite expensive--which is why I downloaded mine from torrent sites. For sheer price alone, I think going for commercial audio tapes can be discouraging. The good news is that you don't really need to buy them. The internet is a great portal for useful, downloadable materials. As I said, I got my pimsleur from mininova (www.mininovao.org). If you know how to download files using torrents, you will have no problem. Moreover, there are commercial language sites that offer free content for download such as Japanesepod101 (www.japanesepod101.com). I especially like Japanesepod 101 because the lessons are arranged according to levels.