In its pure u-form the Norwegian u sounds like in English true or good (keep the vowel long to hear it better).
That said, when spoken rapidly u in du can sound quite differently to its pure form, and quite similar to the computer voice in this case.
Just be careful if you use the rapid-speech-form of u. You might end up saying other vowels instead. And if not obvious from the context it would be a quite different word. For example a few I can think of from the top of my head:
du (you) vs. dø (die) vs. det (this/that)
hurra (hooray) vs. hora (the hooker/the prostitute)
mur ((brick) wall) vs. mor (mother) vs. mør (tender; stiff) vs. mer (more)
and so on...