Translation:We do not speak Federation Standard. Perhaps the Terran speaks Klingon.
Are you asking why speaker icons appear in the course when we have no audio? For that you would have to ask the programmers. It does seem silly.
Or are you asking why we have no audio? That was Duolingo adminstration decision, but they are working on a solution for us.
If you have the Klingon Text-To-Speech app installed, that may be why you're seeing an audio icon. However, sadly, it still doesn't work within the Duolingo app. :( If you do your lessons in a browser, and have the Klingon Text-To-Speech generator installed, THEN the audio should work. (I have it installed, but I don't use it often enough to remember the exact conditions that are required for it to function properly.)