Hi Jonathan,
You can alter the audio setup (I2C register sequences written from the CC85xx to the AIC3204) directly yourself to tweak the setup. There are multiple ways of setting the AIC3204 input up with various gain settings, mic bias etc. If i remember correctly mic_bias is
You will have to study the application reference guide to understand the capabilities of the AIC3204
http://www.ti.com/product/tlv320aic3204
The AIC3204 itself is supported over at:the Audio Converters forum and questions on the inner workings on this device is probably wise to ask there to get the real expert answer.
http://e2e.ti.com/support/data_converters/audio_converters/default.aspx
I personally find looking at the internal block diagram and analog routing diagrams useful.
For better understanding on how to alter and edit the audio device configuration files. please see the Configurators help system under "audio device definition files".
If you need more assistance with the CC85xx setup, please let me know.
Regards,
Kjetil