My initial impression is that unless everyone in the class had the exact same hardware and software (e.g., they all had eDGes) so that the instructor has some degree of control over the students' experience, it can be incredibly time-consuming to support something like that. Embedding audio files within a document is definitely possible in Word 97 and newer for PC. It *may* be possible in Open Office, but not sure about other freeware text editors (not sure about Google either). And you can put specific requirements on software in the syllabus... but invariably there will be a subset who won't abide by it, but then still expect that any difficulty they encounter is your problem to solve. Unless there is someone else available who can provide tech support on an ongoing basis across all platforms, it will often be more trouble than it's worth.

Also, in the specific case, I'm not sure why it would be necessary to embed audio into the file unless the entire class had eDGes. If there was a subset who didn't have eDGes, then I would think it would just be easier to distribute an mp3 or whatever by itself in lieu of a marked up paper. Having a stand-alone--rather than embedded--audio file would probably eliminate most of the tech support issues.