It is like in the sentence
"Nous vous écrivons afin de vous faire part de notre grande inquiétude face à ce qui se passe au Burundi."
"We are extremely concerned about the situation in Burundi, a country adrift in a sea of ethnic violence.
So it is like, we are writing to you about...
Nous is subject and vous is reflexive pronoun. Read this articl: http://french.about.com/od/grammar/a/reflexivepronouns.htm
I have had the same problem with the recording. I tried at least ten or more time and even though my microphone is working perfectly and I can hear myself on the recording, Duolingo keeps saying that it can't hear me or doesn't understand. I ended up having to forcefully Skip this exercises and loose a heart because the program is having some kind of glitch.
Duolingo, please help and fix this glitch.