Here, check this nifty link out which explains what the PSD is actually doing:
http://eahart.com/prius/psd/
Other than the fact this gizmo is load o' fun to play with, it also demonstrates that if the ICE is running at an idle and the car is stopped, the wee-little MG1 is spinning around 4000 RPM, which would explain the whine I hear in my garage at startup. I'd also agree with Droid13: it's a really cool sound. You'll also see why the ICE must come on (at least spin) when the car is doing 42
MPH. Does it actually have anything to do with the whine folks are discussing? Maybe. (Yes, I know the link goes to a Prius PSD, but fundementally, the Prius and TCH are similar.)