Audio Memo could be a viable option for recording voice only productions with students. The real benefit of this (paid) app is the integration options with Google Drive.
View the process.
On a side note, because this is a paid app and the free app only allows sharing via email, we have chosen to set up classroom accounts using soundcloud.com. This is a free option which allows for recording & uploading via the iPad app. See/Hear example
More to come on that when implemented with students next week.