Well, that's a dilemma. I almost automatically wanted to dismiss Google's and Duolingo's (which, I believe is based on the same engine) translation attempts... But at the same time, I believe Google's German text-to-speech should be pretty good by now (in comparison to Welsh, for example, which is the classic robot voice beloved by all). Which is not to say that it can't make mistakes. At the same time, depending on the word you might have missed a diacritic, which would change the pronunciation completely. And, some words, with the same spelling, are pronounced slightly differently depending on the meaning. Although that's only which syllable the stress falls on.

Once again, when in doubt, refer to forvo.com. Or also to the wiktionary. In both of them the pronunciation might be missing for some words, but I think you're still studying the common vocabulary for which it's unlikely.