This option may have been added under the pressure of users who constantly reported it. I don't think it should be accepted, after all, "don't hear" and "can't hear" are different even if you use it interchangeably in English. The goal of translating into English in exercises is not to give the most natural translation but just to confirm that you understand the Spanish sentence correctly.
When you redo the sentence, if it is still happening: https://support.duolingo.com/hc/en-us/articles/204752124-How-do-I-report-a-problem-with-a-sentence-or-translation-
You can submit a bug report, but as you say it has been a year, so I would verify that it has not already been fixed first.
I have said it before and I'll say it again. This is the blind leading the blind. Please think before giving your two cents on what is grammatically correct. Make sure you inform yourself before doing so, or it's just bloody pointless. Wild speculation based on nothing doesn't help anybody. Although it's nice that people take the time to comment, don't get me wrong. :)
There are some valid answers, yes. There are also some that send people completely in the wrong direction. Sorry for the tone of what I wrote before. I can see why you feel I was being condescending. Anyway, I guess what I was trying to say is that perhaps citing sources when giving grammar help would be a good system to introduce. I have posted a link below in another comment if you are still interested.