I'd just like to come up with another option one could think of how voice or audio recordings in general could be recorded and integrated into Moodle - mobile phones and PDAs!
As I already mentioned in some other discussions, I am working on a mobile rich client allowing for mobile access to Moodle via java enabled phones or PDAs.
The thing special about our solution is, that you can make use of the integrated multimedia features the device offers! So audio and voice recording is just the beginning! One can also use the integrated camera to take photographs and what can be even more useful - record video clips.
So coming back to this discussion, the student is able for example to reply to a forum discussion via the app on her phone and directly attach an audio comment! Of course this functionality can easily be extended to other modules like the voice question module, Speex etc.
If you are interested, please do not hesitate to drop me a line or give me a skype call. For the moment our project site www.mobileclassroom.at is mainly in german only
Cheers,
Andreas