Having used audio feedback (mainly Audacity to create the MP3 and then send via email) for some time now I thought the iPod Touch would be worth investigating for the task.
Using the “Voice Memos” function feedback may be easily recorded and as the earphones supplied with the device have microphone capability you have all the equipment you need for the job.
Once feedback has been recorded the file is automatically saved and then can be shared by email. There is also the possibility of doing some light editing by “trimming” the file.
The output file is in the *.m4a format which can be opened in iTunes. It will not play in windows media player however (as far as I can tell) so please make sure that your students are aware of this. Something else to be aware of is that the Voice Memos app is not available on the first generation iPod touch.
I have done some audio recordings on the iPod Touch and the sound quality is excellent. Obviously this is the wrong time of year to be trying the technology with students but I do plan to give it a go in the next academic year. I would be glad to receive any advice from practitioners regularly using the iPod Touch / iPhone to record student feedback.
Lots more on audio feedback can be found on the A Word In Your Ear 2009 – Audio Feedback website and in the communication; Making Small Talk — Audio MP3 Files Made More Portable.