I've noticed that a lot, and I mean A LOT, of the vocal recordings in the Danish lessons lack important glottal stops. I'm not diminishing the Danish team's work in any way because I know that they're are working their butts off, but I feel that this is a key part of Danish pronunciation, and without it people risk finding themselves unable to understand and make themselves understandable to "real" people. I'm not trashing on the hard working people behind this course, I just thing that this is very important and something we have to note.
It would be hard for you to trash the hard work of people on this course on this basis even if you wanted to, since as I understand it they didn't create the text-to-speech engine in use and apparently good Danish text-to-speech engines are hard to come by! If that's true, fixing the problem may not be easy or even viable. Hopefully they can weigh in on that (though as I understand it, it's the Duolingo people who ultimately decide on the text-to-speech stuff).
Although I'm not an expert on the situation (having come in after the course was released), as dnshope said, we have no real control over the text-to-speech (although there are some dialects which don't use the stød) I do agree it is an important part of the speech and can be the difference between "she" and "dog" (hun and hund) or "yellow" and "gold" (gul and guld).
To help people out a little bit more, here are a few resources which might be useful:
Dansk Udtale (link is to the first stød video and is entirely in Danish)
Anders Basby's website is good for general Danish help, but he also has an udtale page which includes "*stødte" vowels and consonants (the udtale page is again, all in Danish
Unfortunately there aren't too many resources on it in English other than the Wikipedia article that I can find
ordnet.dk is good for checking to see if stød is in the word.
You can see the difference in the 'udtale' for hun and hund
The ˀ symbol marks where the stød is in a word.
This map from Wikipedia shows it (though I have no idea how accurate it is, I've never been to the places it shows as not having a stød):
The pink use the Stød the same as rigsdansk, the green have a "musical" accent like Swedish and Norwegian and the blue have no stød