There are a couple of things you can consider:
- Put in a feature request for this (or vote up an existing feature request). https://feedback.coronalabs.com
There is no guarantee that our engineering team will take on this but I know they are going to work on some other audio things, so if there is interest in this, they might add it. The more votes the better.
- Consider Corona Enterprise. This requires a paid subscription (https://coronalabs.com/enterprise) but you can make your own native calls to do this yourself.
Rob