A few months ago I gave an introductory lecture on the ACT concept of defusion to a group of professionals that are participating in an online learning community called Practice Ground, led by Kelly Koerner, a well-known trainer of Dialectical Behavior Therapy. Let me know if you have any feedback. I hope you enjoy them.
Another possibility is to save the mp3 file to your desktop, then play it with Windows Media Player or another similar player. If you right click on the link, there will be a menu item that says something like "Save as..." that will allow you to save it to your desktop. Some people don't have their browsers set up to automatically open up the file in a browser.