Silence during "type the German"
I'm not hearing anything during the exercises in which you have to type the German the woman says to you. Its not a speaker issue; just no audio is playing.
Browser? Operating system? Versions, please.
Sometimes Flash just poops out on me and I stop getting audio. I assume you get audio on the next question?
In your Duolingo settings, do you have "speaker" and "autoplay audio" turned on?
What happens when you restart the browser? The computer?
Do you have any browser settings turned on like "don't autoplay plugins" or something along those lines?
Has it ever worked? When? Were you still using the same browser and computer setup?
No, I'm totally being serious and not trying to be patronizing! (Though yes, years of "no, please humor me and click 'save' to see if your changes will be saved" and "you mean the power to your entire block is out? maybe that explains your computer not working" does engrain a bit of automatic exasperation.)
I'm saying that it didn't take any effort to contemplate and write--it's easy for me to rattle off these steps because they generally work in 99% of any weird browser issue.