Rosetta Stone/Internal Mic not working

I had the same problem, but I think I found a helpful (but imperfect) fix. As it turns out, when you set the microphone preference to 'Internal Microphone,' Rosetta Stone takes it upon itself to change the input volume as it pleases--usually to full. This is bad because the computer will hear a pounding, garbled, static-filled mess instead of the simple word you think you're saying. I don't remember how I got to it, but somewhere in Rosetta's preferences you can listen to how you sound (and visually compare your sound wave to the correct answer so as to tweak your intonation and articulation), and this is where I discovered the problem.

The solution: open System Preferences, go to "Sound," select the "Input" tab, and then set the "Input Volume" to the halfway mark. The computer will hear you much more clearly, and you should do fine on your lessons. Keep System Prefs open throughout the lesson, because Rosetta Stone will actually reset your input volume to full when you first open the program, to 3/4 when you try to calibrate with '1, 2, 3, 4, 5,' and then back up to full if you happen to mess up too many times in a row thereafter.

It's frustrating to have to keep on adjusting the volume while you're trying to concentrate, I know, but at least it gets to the heart of the issue. Perhaps there's a script floating around that can take care of this, but my (admittedly limited) searches have turned up nothing. Such as it is, I hope this helps!