While Brian overheats and I freeze to death, I'll show you an example of comparison data logging with the sound sensor and NXT-G 2.0.
The faint, wavy yellow line is my prediction of what my voice would sound like (graphically speaking) if I counted to ten, speaking into the sound sensor that's connected to the brick in another room. (To be honest, I just drew a squiggly line across the screen, but we'll call it a prediction for purposes of contrast).
The solid line with sharp peaks and valleys is the graphical depiction of my actual voice, rising as I speak and dropping off in the silences in between.
As you can see, my "prediction" is woefully out of sync with my actual voice. Both the predictive and actual lines are overlaid for comparison. You can see the minimum, maximum and mean for each data set if you click the graphic.