Disabling AGC on a Nikon?

I have a Nikon D3200, and boy is AGC annoying! Is there any way firmware or hack or anything that I can use to disable AGC on this camera?

There's only two things you can do: adjust how sensitive the mic is, or turn the sound off.
If you're listening to the sound with the built in camera speaker, you won't ever get sound without any hiss.

While it is maybe an extra step, some video editors have an audio normalization function that might correct any audio issues.