Hello,
That is peculiar. You can still play the recorded files from previous years? The Audio file should automatically play on your Drive (unless media settings have been changed on your Drive or within your Domain)
My Goobric files also give me the option to play with the 'Music Player for Google Drive' add-on, could that be an option ( meaning your students would need this as well if the application does infact play the audio)
I am trying to recreate this issue, I can't imagine how the files would be saving incorrectly but I will see what I can find. Thanks!