Translation:The whole family must sleep in one house.
I've said this before, but to me this is incomprehensible. I know that this is out of your hands, I also know not to expect this to change anytime soon. I just hope enough people raise this issue for the developers to take notice one day and implement what shouldn't be too hard a change.
Incomprehensible is an excellent description of this. There is no reason that the algorithm for checking the answer to a listening exercise should be any different than other exercises. As a software developer for over 40 years, I can pretty much guess what the algorithm is, and it seems to me that you would have to go out of your way to limit a listening exercise to just one answer.
I'd say the distinguishable difference is there, but in a faulty way. At regular speed, I cannot hear any stress of the "et(t)", which according to what has been taught here means it is an "et". At slow speed, the "et(t)" is distinctly stressed, which means it is an "ett".
If the audio cannot be corrected, then it would be best to either accept both "a house" and "one house" as correct (not possible as of four years ago according to replies here), or to allow answering only via wordbank and not via free typing, or to remove this audio exercise from the course.
Either "ett hus" or "et hus" should be accepted. Either ones makes perfect sense. I have never noticed any restrictions where audio exercises can only accept one sentence. I can't believe that is still true. If it is, then change the sentence to something unambiguous. You could just as easily make it "sove i huset" and it would still serve the purpose of teaching the infinitive.
The "Report" option for this exercise does not include "My answer should be accepted". So I'll have to report it here. My answer of "et hus" (not "ett hus") should be accepted. If there are technical reasons why multiple answers cannot be accepted here, then this exercise should either be reworded or removed.