Is the computer voice (quite) off the mark sometimes?
Is it just me or is the computer voice mispronouncing some words? I think I've caught it more than once saying "gu" instead of "du". Case in point, the sentence "Du bist eine Schülerin" from the Occupations segment. I don't know if this is an occasional, but understandable glitch, or if there are greater problems with the computer-generated voices. I can't judge the German voice, but the one used in the Spanish lessons has quite a few bugs that need to be worked out of the system.
@Raymond17: I agree with Christian that the German voice is pretty good in general. (At the moment, the French voice is worst). However, I also have occasionally noticed some clear mispronunciations. (As far as I can tell, the most common errors seem to be in the length of vowels and in wrong stressings). So, I'd say it isn't 100% reliable but it usually gives a pretty good idea. If in doubt, you can check some of the websites with recordings of native speakers or just ask here ;-)
Apart from the words it specifically can't pronounce (e.g. Bär, Gebet) there seem to be some sentences where it makes unrecognisable sounds. The only explanation I can think of, is that there was a spelling error in the original text when the TTS was recorded, which was subsequently corrected, but the audio remained unchanged.
funnily enough, I don't have any problems (so far) with the french voice, but that's probably because it's easier for me to understand badly pronounced french, than when the natives speak it.