That would be entertaining... but we don't currently have any access to the microphone (and not really the speaker either... we can play back stuff but that's using high level functions for playing sound effects, no timing accurate access to a DAC has been discovered).
One thing making low level audio things harder is the fact that Canon uses and has used many different audio chips. So if someone manages to implement something, it may only work on a few cameras roughly the same age and price range.
