Audio recordings are available for the four presentations, in Standard MP3 format. In addition, Dr. Rick Audas' presentation is also available in iTunes/iPod format. The iTunes/iPod version of the recording will allow you to view his presentation slides in the video window.
To listen to the audio, simply click on the hyperlink below. If this doesn't work, right-click and choose 'Save Target As...'. Save the audio file to the appropriate directory and then bring up either iTunes/iPod, RealPlayer or other media software. Finally, open the file which you have saved.